ci: add labeler to replace mergify

.github/labeler.yml

@@ -0,0 +1,21 @@
+configuration:
+  - changed-files:
+    - any-glob-to-any-file:
+      - '**/*.yml'
+      - Dockerfile
+      - .shellcheckrc
+      - Makefile
+
+documentation:
+  - changed-files:
+    - any-glob-to-any-file:
+      - docs/**
+      - '**/*.md'
+
+source:
+  - changed-files:
+    - any-glob-to-any-file: src/**
+
+test:
+  - changed-files:
+    - any-glob-to-any-file: test/**

.github/workflows/labeler.yml

@@ -0,0 +1,19 @@
+---
+
+name: Pull Request Labeler
+on:
+  pull_request_target:
+
+permissions:
+  contents: read
+
+jobs:
+  labeler:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - uses: actions/labeler@8558fd74291d67161a8a78ce36a881fa63b766a9 #v5.0.0
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}