replace lintr with air

Author: wlandau

.github/workflows/air.yaml

@@ -0,0 +1,19 @@
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+
+name: lint
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install
+        uses: posit-dev/setup-air@v1
+
+      - name: Format
+        run: air format .