Update gcovr requirement from >=7.2 to >=8.6 (#35)

Updates the requirements on [gcovr](https://github.com/gcovr/gcovr) to
permit the latest version.
<details>
<summary>Release notes</summary>
<p><em>Sourced from <a
href="https://github.com/gcovr/gcovr/releases">gcovr's
releases</a>.</em></p>
<blockquote>
<h2>8.6</h2>
<p>Breaking changes:</p>
<ul>
<li>Drop support for Python 3.9. (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1227">#1227</a>)</li>
</ul>
<p>New features and notable changes:</p>
<ul>
<li>Add support for Python 3.14. (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1227">#1227</a>)</li>
</ul>
<p>Bug fixes and small improvements:</p>
<ul>
<li>To avoid merge errors, add the line number to the name of the
unknown function. (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1229">#1229</a>)</li>
<li>If intermediate files are kept, rename the gcov files before
processing them to log the
final filename. (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1230">#1230</a>)</li>
<li>Use the first line after a function definition and not the first
line which is hit. (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1231">#1231</a>)</li>
</ul>
</blockquote>
</details>
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/gcovr/gcovr/blob/main/CHANGELOG.rst">gcovr's
changelog</a>.</em></p>
<blockquote>
<h2>8.6 (13 January 2026)</h2>
<p>Breaking changes:</p>
<ul>
<li>Drop support for Python 3.9. (:issue:<code>1227</code>)</li>
</ul>
<p>New features and notable changes:</p>
<ul>
<li>Add support for Python 3.14. (:issue:<code>1227</code>)</li>
</ul>
<p>Bug fixes and small improvements:</p>
<ul>
<li>To avoid merge errors, add the line number to the name of the
unknown function. (:issue:<code>1229</code>)</li>
<li>If intermediate files are kept, rename the gcov files before
processing them to log the
final filename. (:issue:<code>1230</code>)</li>
<li>Use the first line after a function definition and not the first
line which is hit. (:issue:<code>1231</code>)</li>
</ul>
<p>.. _release_8_5:</p>
<h2>8.5 (08 January 2026)</h2>
<p>Known bugs:</p>
<ul>
<li>:ref:<code>fix_1229</code></li>
<li>:ref:<code>fix_1231</code></li>
</ul>
<p>Breaking changes:</p>
<ul>
<li>
<p>The option :option:<code>--lcov-test-name</code> doesn't accept
values with spaces anymore. (:issue:<code>1196</code>)</p>
</li>
<li>
<p>The option :option:<code>--lcov-format-1.x
&lt;--lcov-format-1&gt;</code> is deprecated and mapped to
:option:<code>--lcov-format-version=1.x</code>.
(:issue:<code>1212</code>)</p>
</li>
<li>
<p>Changes to HTML templates:</p>
<ul>
<li>The file overview table in the default theme now uses a grid layout.
(:issue:<code>1216</code>)</li>
<li>The function lists table in both themes are changed to a grid
layout. (:issue:<code>1216</code>)</li>
<li>Add a common template folder where the common templates for the
themes are stored.
It contains the function content and source page navigation templates.
(:issue:<code>1216</code>)</li>
<li>Restructure the the summary and move some data to the footer.
(:issue:<code>1217</code>)</li>
<li>Add sorting by clicking on the headers of the file overview table
and the function table. (:issue:<code>1219</code>)</li>
<li>Add common stylesheet for all themes.
(:issue:<code>1220</code>)</li>
<li>Add navigation links to source details.
(:issue:<code>1220</code>)</li>
<li>Add buttons to toggle line background color in source details view.
(:issue:<code>1221</code>)</li>
<li>Add a document overview with all active lines in source details
view. (:issue:<code>1222</code>)</li>
<li>Added :option:<code>--html-static-report</code> and remove argument
from :option:<code>--html-single-page</code>.
(:issue:<code>1224</code>)</li>
</ul>
</li>
</ul>
<p>New features and notable changes:</p>
<ul>
<li>Due to added support for LLVM source based code coverage format some
configuration file
keys got changed. The old <code>gcov</code> named options are still
supported but they also affect the</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/gcovr/gcovr/commit/e01ad73582821b5f90e079482164f8e885121e57"><code>e01ad73</code></a>
Release 8.6 (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1232">#1232</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/aefc4ad48ef1c18fe2a2bbc9c270118b356a5f29"><code>aefc4ad</code></a>
Fix possible wrong line number for function (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1231">#1231</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/9916edc93e4e23500b9138c202eaf887d5036874"><code>9916edc</code></a>
Rename files before processing them (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1230">#1230</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/190462cd2c20da3f30a766b7bc15a36378429f2a"><code>190462c</code></a>
Avoid merge errors for lines of unknown functions (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1229">#1229</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/083420c9e6d697040011dbacf90e371c821f5100"><code>083420c</code></a>
Fix bump_version.py if header in python script is missing</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/5d3ec0128efc7e8523867021aed9f079901b2300"><code>5d3ec01</code></a>
Update supported python versions (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1227">#1227</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/a29f06e5d94c88cb6c4afc63caedf2e7511002f0"><code>a29f06e</code></a>
Prepare next iteration (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1226">#1226</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/71eedb8f300612d4095f2ffa4ac60e3fdd58c192"><code>71eedb8</code></a>
Release 8.5 (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1225">#1225</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/d67d90c2c27373e099c2a3298d022f14f5adbac9"><code>d67d90c</code></a>
Add option for static HTML report (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1224">#1224</a>)</li>
<li><a
href="https://github.com/gcovr/gcovr/commit/36fce2a965aac09714cfb1c63e6d4f65122548b1"><code>36fce2a</code></a>
Ensure coverage for function line in LCOV report (<a
href="https://redirect.github.com/gcovr/gcovr/issues/1212">#1212</a>)</li>
<li>Additional commits viewable in <a
href="https://github.com/gcovr/gcovr/compare/7.2...8.6">compare
view</a></li>
</ul>
</details>
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</details>

Author: steve-downey

pyproject.toml

@@ -10,7 +10,7 @@ dependencies = []
 dev = [
     "cmake==4.3.1",
     "clang-format==22.1.3",
-    "gcovr>=7.2",
+    "gcovr>=8.6",
     "pre-commit>=3.7.1",
 ]