skip CLA check for bot accounts in CI workflow

Add a bot detection step that checks if the PR author's login ends
with [bot] (e.g. dependabot[bot], github-actions[bot], renovate[bot]).
When detected, the CLA check is skipped with a success status, and the
CLA assistant action is not invoked at all. This fixes CLA failures on
automated dependency PRs where the allowlist in the CLA assistant
action was not matching correctly.

Author: aconite33

.github/workflows/cla.yml

@@ -50,9 +50,34 @@ jobs:
             -f context="CLAAssistant" \
             -f description="CLA check skipped — author is an org member"
 
+      - name: Check if author is a bot
+        id: bot-check
+        if: github.event_name == 'pull_request_target'
+        env:
+          GH_TOKEN: ${{ steps.app-token.outputs.token }}
+        run: |
+          AUTHOR="${{ github.event.pull_request.user.login }}"
+          AUTHOR_TYPE=$(gh api "users/${AUTHOR}" --jq '.type' 2>/dev/null || echo "Unknown")
+          if [ "$AUTHOR_TYPE" = "Bot" ]; then
+            echo "is_bot=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "is_bot=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Skip CLA for bots
+        if: steps.bot-check.outputs.is_bot == 'true' && github.event_name == 'pull_request_target'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh api --method POST "repos/${{ github.repository }}/statuses/${{ github.event.pull_request.head.sha }}" \
+            -f state=success \
+            -f context="CLAAssistant" \
+            -f description="CLA check skipped — author is a bot"
+
       - name: "CLA Assistant"
         if: |
           (steps.membership.outputs.is_member != 'true') &&
+          (steps.bot-check.outputs.is_bot != 'true') &&
           ((github.event.comment.body == 'recheck' || github.event.comment.body == 'I have read the CLA Document and I hereby sign the CLA') || github.event_name == 'pull_request_target')
         uses: contributor-assistant/github-action@v2.6.1
         env: