workflows: add plugin ci workflow

Author: LeoKle

.github/workflows/plugin-ci.yml

@@ -0,0 +1,24 @@
+name: Plugin CI
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'plugin/**'
+      - '.github/**'
+  pull_request:
+    paths:
+      - 'plugin/**'
+      - '.github/**'
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Check formatting
+        uses: ./.github/actions/plugin/lint
+        with:
+          source-dir: plugin