Use hadolint to check dockerfile

.github/workflows/ci.yml

@@ -5,6 +5,17 @@ on:
     pull_request:
 
 jobs:
+    lint:
+        name: Docker Lint
+        runs-on: ubuntu-latest
+        steps:
+          - name: Checkout
+            uses: actions/checkout@v3
+          - name: Lint Dockerfile
+            uses: hadolint/hadolint-action@master
+            with:
+                dockerfile: Dockerfile
+                ignore: DL3007,DL3018 # Ignore using latest on mlocati/php-extension-installer & version in apk add
     build:
         name: Docker build
         runs-on: ubuntu-latest