Add license finder workflow and approvals

.github/workflows/licensing.yml

@@ -0,0 +1,24 @@
+name: Verify dependency licenses
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+
+jobs:
+  licensing:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.2'
+      - run: gem install license_finder
+      - run: license_finder

doc/dependency_decisions.yml

@@ -0,0 +1,38 @@
+---
+- - :permit
+  - MIT
+  - :who:
+    :why:
+    :versions: []
+    :when: 2023-11-29 19:28:35.943736000 Z
+- - :permit
+  - Apache 2.0
+  - :who:
+    :why:
+    :versions: []
+    :when: 2023-11-29 19:28:58.769927000 Z
+- - :permit
+  - New BSD
+  - :who:
+    :why:
+    :versions: []
+    :when: 2023-11-29 19:29:30.950785000 Z
+- - :permit
+  - Simplified BSD
+  - :who:
+    :why:
+    :versions: []
+    :when: 2023-11-29 19:29:39.698237000 Z
+- - :permit
+  - Mozilla Public License 2.0
+  - :who:
+    :why:
+    :versions: []
+    :when: 2023-11-29 19:29:49.185926000 Z
+- - :license
+  - github.com/DataDog/sketches-go
+  - Apache 2.0
+  - :who:
+    :why:
+    :versions: []
+    :when: 2023-11-29 19:30:26.817927000 Z