fix workflow does not contain permissions (#2355)

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Author: Simek

.github/workflows/vercel-cleanup-data-blobs.yml

@@ -7,6 +7,9 @@ on:
     # Run three time a week on Tuesday, Thursday, and Saturday at midnight - https://crontab.guru/#0 0 * * 2,4,6
     - cron: '0 0 * * 2,4,6'
 
+permissions:
+  contents: read
+
 jobs:
   build:
     runs-on: ubuntu-latest