ci: add license checker

Author: jamesbhobbs

.github/workflows/check-licenses.yml

@@ -0,0 +1,23 @@
+name: Check Licenses
+on:
+  push:
+    branches: ["main"]
+  pull_request:
+    branches: ["*"]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check_licenses:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Base Setup
+        uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1
+        
+      - name: Check Licenses
+        run: jlpm check-licenses
+

package.json

@@ -36,6 +36,7 @@
         "build:labextension:dev": "jupyter labextension build --development True .",
         "build:lib": "tsc --sourceMap",
         "build:lib:prod": "tsc",
+        "check-licenses": "license-checker-rseidelsohn --onlyAllow 'MIT;Apache-2.0;BSD-2-Clause;BSD-3-Clause;ISC;0BSD;CC0-1.0;Python-2.0;CC-BY-3.0;CC-BY-4.0;Unlicense;BlueOak-1.0.0;(MIT OR Apache-2.0);(MIT AND BSD-3-Clause);(Apache-2.0 OR MIT);(BSD-2-Clause OR MIT OR Apache-2.0);(MIT OR CC0-1.0);(MIT AND CC-BY-3.0);(Unlicense OR Apache-2.0)'",
         "clean": "jlpm clean:lib",
         "clean:lib": "rimraf lib tsconfig.tsbuildinfo",
         "clean:lintcache": "rimraf .eslintcache .stylelintcache",
@@ -78,6 +79,7 @@
         "eslint-config-prettier": "^8.8.0",
         "eslint-plugin-prettier": "^5.0.0",
         "jest": "^29.2.0",
+        "license-checker-rseidelsohn": "^4.4.2",
         "mkdirp": "^1.0.3",
         "npm-run-all2": "^7.0.1",
         "prettier": "^3.0.0",
@@ -208,5 +210,6 @@
             "selector-no-vendor-prefix": null,
             "value-no-vendor-prefix": null
         }
-    }
+    },
+    "packageManager": "yarn@1.22.22+sha512.a6b2f7906b721bba3d67d4aff083df04dad64c399707841b7acf00f6b133b7ac24255f2652fa22ae3534329dc6180534e98d17432037ff6fd140556e2bb3137e"
 }