Revert "Bump actions/attest-build-provenance in the actions group (#2)"

This reverts commit 3365fa2.

Author: hoodmane

.github/workflows/main.yaml

@@ -62,7 +62,7 @@ jobs:
           merge-multiple: true
 
       - name: Generate artifact attestation(s)
-        uses: actions/attest-build-provenance@c074443f1aee8d4aeeae555aebba3282517141b2 # v2.2.3
+        uses: actions/attest-build-provenance@7668571508540a607bdfd90a87a560489fe372eb # v2.1.0
         with:
           subject-path: "upload/*.tar.bz2"