ci(timeout): increase xdist-enforcement job timeout from 5 to 10 minutes

Profile results show the job runs 4 test steps with 2-3x CI I/O overhead.
Local execution takes ~30-60s, but CI can take 2-5 minutes with variance.
The 5-minute timeout was too tight, causing intermittent timeouts.

Changes:
- Increased timeout-minutes from 5 to 10 (2x safety margin)
- Added inline comment explaining the profiling rationale

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: vishnu2kmohan

.github/workflows/ci.yaml

@@ -175,7 +175,9 @@ jobs:
   xdist-enforcement:
     name: Validate Pytest-xdist Isolation
     runs-on: ubuntu-latest
-    timeout-minutes: 5
+    # Increased from 5 to 10 minutes (2x safety margin)
+    # Profile results: Local ~10s for xdist tests, but CI has 4 steps with 2-3x I/O overhead
+    timeout-minutes: 10
     steps:
       - name: Checkout code
         uses: actions/checkout@v5