Update GitHub Actions workflow for branch handling

Should work with coding agent

Author: sgbaird

.github/workflows/copilot-setup-steps.yml

@@ -18,6 +18,18 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          # Ensures we check out the actual head branch on PRs
+          ref: ${{ github.head_ref || github.ref_name }}
+
+      - name: Derive branch name
+        id: branch
+        shell: bash
+        run: |
+          BN="${GITHUB_HEAD_REF:-$GITHUB_REF_NAME}"
+          if [ -z "$BN" ]; then BN="$(git branch --show-current || true)"; fi
+          echo "BRANCH_NAME=$BN" | tee -a "$GITHUB_ENV"
+          echo "name=$BN" >> "$GITHUB_OUTPUT"
 
       - name: Set up Python
         uses: actions/setup-python@v5
@@ -32,9 +44,9 @@ jobs:
           python -m pip install tox pre-commit
           # pre-commit run --all-files
           # npx mint-mcp add docs.prefect.io
-          # pre-commit install # don't install, since this has been a source of issues
+          # pre-commit install
 
       - name: Install branch-specific dependencies
-        if: ${{ github.ref_name == 'copilot/fix-382' }}
+        if: ${{ env.BRANCH_NAME == 'copilot/fix-382' }}
         run: |
           python -m pip install "ax-platform<1" prefect prefect-slack