[CI] Add automatic labeler bot for pull requests

.github/labeler.yml

@@ -0,0 +1,13 @@
+'task:mpi':
+  - "tasks/mpi"
+'task:omp':
+  - "tasks/omp"
+'task:seq':
+  - "tasks/seq"
+'task:stl':
+  - "tasks/stl"
+'task:tbb':
+  - "tasks/tbb"
+ci:
+  - ".github"
+  - "appveyor.yml"

.github/workflows/labeler.yml

@@ -0,0 +1,19 @@
+name: "Label PRs"
+
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  auto-label:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Apply labels based on changed files
+        uses: actions/labeler@v5
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          configuration-path: ".github/labeler.yml"