refactor: use --no-project flag instead of direct pytest execution

Instead of calling .venv/bin/pytest directly, use uv's --no-project flag
which avoids discovering the project/workspace and lockfile entirely.

This is cleaner and more cross-platform than the shell script approach,
while achieving the same goal: ensuring lowest-direct tests use only
the packages installed by --resolution lowest-direct without any
interference from the lockfile.

- lowest-direct: uv run --no-project --no-sync pytest
- highest: uv run --frozen --no-sync pytest

Author: felixweinberger

.github/workflows/shared.yml

@@ -77,13 +77,7 @@ jobs:
           uv run --frozen --no-sync python -c "from importlib.metadata import version; print('anyio version:', version('anyio'))" || echo "Failed with --frozen"
 
       - name: Run pytest
-        shell: bash
-        run: |
-          if [ "${{ matrix.dep-resolution.name }}" == "lowest-direct" ]; then
-            .venv/bin/pytest
-          else
-            uv run --frozen --no-sync pytest
-          fi
+        run: uv run ${{ matrix.dep-resolution.name == 'lowest-direct' && '--no-project --no-sync' || '--frozen --no-sync' }} pytest
 
   readme-snippets:
     runs-on: ubuntu-latest