fix: install hadolint in workflow and correct paths filter

Author: xnoto

.github/workflows/buildah.yml

@@ -6,8 +6,8 @@ on:
     branches:
       - main
     paths:
-      - '*/Containerfile'
-      - '.github/workflows/build.yml'
+      - '*/**'
+      - '.github/workflows/buildah.yml'
   workflow_dispatch:
     inputs:
       image:
@@ -54,6 +54,12 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Install hadolint
+        run: |
+          curl -sSL -o /usr/local/bin/hadolint \
+            https://github.com/hadolint/hadolint/releases/download/v2.12.0/hadolint-Linux-x86_64
+          chmod +x /usr/local/bin/hadolint
+
       - name: Run pre-commit
         uses: pre-commit/action@v3.0.1