[StepSecurity] Apply security best practices

Signed-off-by: StepSecurity Bot <bot@stepsecurity.io>

Author: stepsecurity-app[bot]

.github/workflows/build.yml

@@ -8,6 +8,9 @@ on:
       - main
       - stable/**
 
+permissions:
+  contents: read
+
 jobs:
   image:
     name: ${{ matrix.name }}
@@ -40,7 +43,12 @@ jobs:
       packages: write
       pull-requests: write
     steps:
-      - uses: vexxhost/docker-atmosphere/.github/actions/build-image@main
+      - name: Harden the runner (Audit all outbound calls)
+        uses: step-security/harden-runner@a90bcbc6539c36a85cdfeb73f7e2f433735f215b # v2.15.0
+        with:
+          egress-policy: audit
+
+      - uses: vexxhost/docker-atmosphere/.github/actions/build-image@672cf56c8b828e444b6e7906d0ee355c7ec1dea9 # main
         with:
           image-name: ${{ matrix.image-name }}
           build-args: FROM=${{ matrix.from }}