added gh action to create phpmyadmin package if it is updated

.github/workflows/phpmyadmin.yaml

@@ -0,0 +1,45 @@
+name: Build and deploy phpmyadmin
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - "phpmyadmin/**"
+
+env:
+  IMAGE_NAME: phpmyadmin-nowdb
+
+jobs:
+  push_phpmyadmin:
+    if: github.event_name == 'push'
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build image
+        run: docker build -t phpmyadmin-nowdb phpmyadmin -f phpmyadmin/Dockerfile --tag $IMAGE_NAME
+
+      - name: Log in to registry
+        run: echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
+
+      - name: Push image
+        run: |
+          IMAGE_ID=ghcr.io/${{ github.repository_owner }}/$IMAGE_NAME
+
+          # This changes all uppercase characters to lowercase.
+          IMAGE_ID=$(echo $IMAGE_ID | tr '[A-Z]' '[a-z]')
+
+          # This strips the git ref prefix from the version.
+          VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
+
+          # This strips the "v" prefix from the tag name.
+          [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
+
+          VERSION=latest
+          echo IMAGE_ID=$IMAGE_ID
+          echo VERSION=$VERSION
+          docker tag $IMAGE_NAME $IMAGE_ID:$VERSION
+          docker push $IMAGE_ID:$VERSION