fix(ci): skip Codecov upload for dependabot PRs

Dependabot PRs don't have access to repository secrets, causing
Codecov upload to fail with "Token required because branch is
protected". Skip the upload step when actor is dependabot[bot].

Author: tbhb

.github/workflows/ci.yml

@@ -96,7 +96,7 @@ jobs:
         run: just test-coverage
 
       - name: Upload coverage to Codecov
-        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.10'
+        if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.10' && github.actor != 'dependabot[bot]'
         uses: codecov/codecov-action@5a1091511ad55cbe89839c7260b706298ca349f7 # v5.5.1
         env:
           CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}