cicd: add a github workflow for xfails report script (flashinfer-ai#2273)

<!-- .github/pull_request_template.md -->

## 📌 Description

Adds workflow that runs weekly on Mondays (and can be triggered
manually) to execute scripts/xfails_tracker.py, which scans the test
suite for xfail markers and outputs a comprehensive report to
reports/xfails_report.txt. If the report has changed, it automatically
creates a pull request to commit the updated report to the repository.

## 🔍 Related Issues

cont. testing item from november roadmap

## 🚀 Pull Request Checklist

Thank you for contributing to FlashInfer! Before we review your pull
request, please make sure the following items are complete.

### ✅ Pre-commit Checks

- [x] I have installed `pre-commit` by running `pip install pre-commit`
(or used your preferred method).
- [x] I have installed the hooks with `pre-commit install`.
- [x] I have run the hooks manually with `pre-commit run --all-files`
and fixed any reported issues.

> If you are unsure about how to set up `pre-commit`, see [the
pre-commit documentation](https://pre-commit.com/).

## 🧪 Tests

- [x] Tests have been added or updated as needed.
- [x] All tests are passing (`unittest`, etc.).

## Reviewer Notes

<!-- Optional: anything you'd like reviewers to focus on, concerns, etc.
-->


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Chores**
* Added an automated weekly report generation that detects changes and
opens pull requests to incorporate updates.
* Updated automation to remove generated-attribution boilerplate from
automated commit/PR messages.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: kahyunnam

.github/workflows/update-codeowners.yml

@@ -73,10 +73,6 @@ jobs:
             chore: update CODEOWNERS based on git history
 
             Auto-generated CODEOWNERS update based on commit activity over the last ${{ env.DAYS_BACK }} days.
-
-            🤖 Generated with [Claude Code](https://claude.com/claude-code)
-
-            Co-Authored-By: Claude <[email protected]>
           branch: auto-update-codeowners
           base: main
           delete-branch: true

.github/workflows/update-xfails-report.yml

@@ -0,0 +1,102 @@
+name: Update XFails Report
+
+on:
+  schedule:
+    # Run weekly on Monday at 00:00 UTC
+    - cron: '0 0 * * 1'
+  workflow_dispatch: # Allow manual triggering
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  update-xfails-report:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - name: Checkout repository
+        uses: actions/[email protected]
+        with:
+          fetch-depth: 1 # Shallow clone is sufficient for scanning test files
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Create reports directory
+        run: mkdir -p reports
+
+      - name: Run XFails tracker
+        run: |
+          python scripts/xfails_tracker.py > reports/xfails_report.txt 2>&1 || {
+            echo "Error: XFails tracker script failed"
+            cat reports/xfails_report.txt
+            exit 1
+          }
+
+      - name: Check for changes
+        id: check_changes
+        run: |
+          # Check if xfails report file is new (unstaged) or has changes
+          if git ls-files --error-unmatch reports/xfails_report.txt >/dev/null 2>&1; then
+            # File is tracked, check for changes
+            if git diff --quiet reports/xfails_report.txt; then
+              echo "changed=false" >> $GITHUB_OUTPUT
+              echo "No changes detected in xfails report"
+            else
+              echo "changed=true" >> $GITHUB_OUTPUT
+              echo "Changes detected in xfails report"
+            fi
+          else
+            # File is untracked (newly created)
+            echo "changed=true" >> $GITHUB_OUTPUT
+            echo "XFails report file is new"
+          fi
+
+      - name: Create Pull Request
+        if: steps.check_changes.outputs.changed == 'true'
+        uses: peter-evans/create-pull-request@v7
+        with:
+          token: ${{ secrets.FLASHINFER_BOT_TOKEN }}
+          committer: flashinfer-bot <[email protected]>
+          author: flashinfer-bot <[email protected]>
+          commit-message: |
+            chore: update xfails report
+
+            Auto-generated xfails report based on current test suite markers.
+          branch: auto-update-xfails-report
+          base: main
+          delete-branch: true
+          title: 'chore: Update XFails Report'
+          body: |
+            ## Summary
+
+            This PR updates the xfails report based on the current test suite.
+
+            ## Changes
+
+            - Updated `reports/xfails_report.txt` with current xfail markers from the test suite
+
+            ## How to Review
+
+            1. Review the changes to `reports/xfails_report.txt`
+            2. Check if the number of xfails has increased or decreased
+            3. Review the reasons for any new xfails
+            4. Consider addressing xfails that may no longer be needed
+
+            ## Notes
+
+            - This is an automated PR generated weekly
+            - The report shows all `pytest.mark.xfail` markers in the test suite
+            - Grouped by reason for easy analysis
+
+            ---
+
+            🤖 This PR was automatically generated by the [update-xfails-report workflow](.github/workflows/update-xfails-report.yml)
+          labels: |
+            automated
+            maintenance
+            testing