update dependabot config and pin to released tag (#520)

Signed-off-by: Carlos Panato <ctadeu@gmail.com>

.github/dependabot.yml

@@ -22,3 +22,13 @@ updates:
         update-types:
           - "minor"
           - "patch"
+
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: weekly
+    groups:
+      docker:
+        update-types:
+          - "patch"
+          - "minor"

.github/workflows/release.yaml

@@ -51,7 +51,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-go-
 
-      - uses: chainguard-dev/actions/goimports@main
+      - uses: chainguard-dev/actions/goimports@5363dd9eb48083bbf7674a4bbe62d71c3b230edd # v1.1.2
 
       - name: Login to registry
         if: github.repository == 'helm/chart-releaser'