fix: rename variable for clarity in daily-benchmark.yml

- Changed `releaseExists` to `tagExists` for better understanding of the variable's purpose.
- This update improves code readability and aligns with the context of checking tag existence in the release process.

Author: ImBIOS

.github/workflows/daily-benchmark.yml

@@ -258,7 +258,7 @@ jobs:
             const fs = require('fs');
             const tagName = '${{ needs.analysis.outputs.tag-name }}';
             const releaseName = '${{ needs.analysis.outputs.release-name }}';
-            const releaseExists = '${{ needs.analysis.outputs.release-exists }}' === 'true';
+            const tagExists = '${{ needs.analysis.outputs.release-exists }}' === 'true';
             const descriptionFile = '${{ needs.analysis.outputs.description-file }}';
 
             let releaseBody = 'No benchmark results available.';