Update actions/attest-build-provenance action to v2

Author: renovate-bot

.github/workflows/test-buildenv-l1-container.yml

@@ -28,7 +28,7 @@ jobs:
 
       - name: Generate SLSA Provenance
         id: slsa
-        uses: actions/attest-build-provenance@ef244123eb79f2f7a7e75d99086184180e6d0018 # v1.4.4
+        uses: actions/attest-build-provenance@520d128f165991a6c774bcb264f323e3d70747f4 # v2.2.0
         with:
           subject-name: "test_l1"
           subject-digest: ${{ steps.build.outputs.digest }}

.github/workflows/test-buildenv-l2-container.yml

@@ -48,7 +48,7 @@ jobs:
 
       - name: Generate SLSA Provenance
         id: slsa
-        uses: actions/attest-build-provenance@ef244123eb79f2f7a7e75d99086184180e6d0018 # v1.4.4
+        uses: actions/attest-build-provenance@520d128f165991a6c774bcb264f323e3d70747f4 # v2.2.0
         with:
           subject-name: "test_l2"
           subject-digest: ${{ steps.build.outputs.digest }}