Update github actions, add dependabot to handle future updates

.github/dependabot.yml

@@ -0,0 +1,10 @@
+# Set update schedule for GitHub Actions
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every weekday
+      interval: "daily"

.github/workflows/docker-publish.yml

@@ -37,7 +37,7 @@ jobs:
       # https://github.com/docker/login-action
       - name: Log into registry ${{ env.REGISTRY }}
         if: github.event_name != 'pull_request'
-        uses: docker/login-action@28218f9b04b4f3f62068d7b6ce6ca5b26e35336c
+        uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
@@ -47,15 +47,15 @@ jobs:
       # https://github.com/docker/metadata-action
       - name: Extract Docker metadata
         id: meta
-        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
+        uses: docker/metadata-action@3a3bb3a81753dc99f090d24ee7e5343838b73a96
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           flavor: latest=true
 
       # Build and push Docker image with Buildx (don't push on PR)
       # https://github.com/docker/build-push-action
       - name: Build and push Docker image
-        uses: docker/build-push-action@ad44023a93711e3deb337508980b4b5e9bcdc5dc
+	uses: docker/build-push-action@a66e35b9cbcf4ad0ea91ffcaf7bbad63ad9e0229
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}