fix: drop pilot/plugin.json from semantic-release prepareCmd

The 8.8.0 release pipeline failed because the prepareCmd's sed step
referenced pilot/plugin.json, which was deleted in #143. Remove it from
both the sed list (prepare step) and the @semantic-release/git assets
list so the next release cycle can bump versions cleanly.

Also confirmed no other tracked file (CI workflows, install.sh, etc.)
references the removed pilot/plugin.json — only intentional refs in
_remove_legacy_plugin_marker's docstring + the test asserting we skip
it during install.

Author: maxritter

.releaserc.json

@@ -24,13 +24,13 @@
     [
       "@semantic-release/exec",
       {
-        "prepareCmd": "sed -i 's/^__version__ = \".*\"/__version__ = \"${nextRelease.version}\"/' installer/__init__.py launcher/__init__.py && sed -i 's/export VERSION=[0-9.]*/export VERSION=${nextRelease.version}/g' README.md && sed -i 's/\"version\": \"[0-9.]*\"/\"version\": \"${nextRelease.version}\"/' console/package.json pilot/package.json pilot/plugin.json"
+        "prepareCmd": "sed -i 's/^__version__ = \".*\"/__version__ = \"${nextRelease.version}\"/' installer/__init__.py launcher/__init__.py && sed -i 's/export VERSION=[0-9.]*/export VERSION=${nextRelease.version}/g' README.md && sed -i 's/\"version\": \"[0-9.]*\"/\"version\": \"${nextRelease.version}\"/' console/package.json pilot/package.json"
       }
     ],
     [
       "@semantic-release/git",
       {
-        "assets": ["installer/__init__.py", "launcher/__init__.py", "README.md", "CHANGELOG.md", "console/package.json", "pilot/package.json", "pilot/plugin.json"],
+        "assets": ["installer/__init__.py", "launcher/__init__.py", "README.md", "CHANGELOG.md", "console/package.json", "pilot/package.json"],
         "message": "chore(release): ${nextRelease.version} [skip ci]\n\n${nextRelease.notes}"
       }
     ],