ci: revert ci.yml exclusion from detect-changes

The exclusion caused code-changed to be false for CI-only PRs, skipping
all test jobs including ubuntu.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Boshen

.github/workflows/ci.yml

@@ -52,7 +52,6 @@ jobs:
             code:
               - '**'
               - '!**/*.md'
-              - '!.github/workflows/ci.yml'
 
   download-previous-rolldown-binaries:
     needs: detect-changes