move public key from secret to variable

Author: fennifith

.github/workflows/fly.yml

@@ -37,4 +37,4 @@ jobs:
         env:
           TYPESENSE_ADMIN_API_KEY: ${{ secrets.TYPESENSE_ADMIN_API_KEY }}
           TYPESENSE_WRITE_API_KEY: ${{ secrets.TYPESENSE_WRITE_API_KEY }}
-          TYPESENSE_PUBLIC_API_KEY: ${{ secrets.TYPESENSE_PUBLIC_API_KEY }}
+          TYPESENSE_PUBLIC_API_KEY: ${{ vars.TYPESENSE_PUBLIC_API_KEY }}