Update pelican[markdown] requirement in /pelican

Updates the requirements on [pelican[markdown]](https://github.com/getpelican/pelican) to permit the latest version.
- [Release notes](https://github.com/getpelican/pelican/releases)
- [Changelog](https://github.com/getpelican/pelican/blob/main/docs/changelog.rst)
- [Commits](https://github.com/getpelican/pelican/commits)

---
updated-dependencies:
- dependency-name: pelican[markdown]
  dependency-version: 4.11.0.post0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pelican/pyproject.toml

@@ -67,7 +67,7 @@ dependencies = [
 # and runs mypy / pylint out of the resulting venv.
 [dependency-groups]
 dev = [
-    "pelican[markdown]>=4.11,<4.12",
+    "pelican[markdown]>=4.11.0.post0,<4.12",
     "ruff>=0.6",
     "pytest>=8",
     "mypy>=1.10",