Update ghcr.io/enterprise-contract/golden-container:latest Docker digest to a3a860d (#376)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/checks.yaml

@@ -20,7 +20,7 @@ jobs:
     - name : Run EC Validate (keyless)
       uses: ./
       with:
-        image: ghcr.io/enterprise-contract/golden-container:latest@sha256:fe90592757fb4a4fee9c34ca38f3d4d0174000b2f49848a0a657669556874bbf # latest
+        image: ghcr.io/enterprise-contract/golden-container:latest@sha256:a3a860d0124d545ef062cf7039c55fb84ad91fff454f616bc13bc79a55b2d815 # latest
         identity: https:\/\/github\.com\/(slsa-framework\/slsa-github-generator|enterprise-contract\/golden-container)\/
         issuer: https://token.actions.githubusercontent.com