Upgrade GitHub Actions to latest versions for improved functionality

Author: isontheline

.github/workflows/buildx.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Prepare
         id: prepare
         run: |
@@ -51,7 +51,7 @@ jobs:
           docker buildx build --output "type=image,push=false" ${{ steps.prepare.outputs.buildx_args }}
       - name: Login to DockerHub
         if: success() && github.event_name != 'pull_request'
-        uses: docker/login-action@v1
+        uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}