ci: tell ShipIt to skip commits with invalid conventional format (#775)

Dependabot PR #772 merged with a non-conventional commit title
("Bump the python-dependencies group with 8 updates"), which caused
ShipIt to abort. Adding --skip-invalid-commit lets ShipIt log a warning
and continue past such commits instead of failing the release workflow.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dbrattli

.github/workflows/python-publish.yml

@@ -31,7 +31,7 @@ jobs:
         run: dotnet tool restore
 
       - name: Run ShipIt
-        run: dotnet shipit --pre-release rc --allow-branch master
+        run: dotnet shipit --pre-release rc --allow-branch master --skip-invalid-commit
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}