Adopt license compliance scripts into workflows, docs

This commit introduces the use of `go-licenses` within CI/CD and manual processes for generating / updating the license information used by GitHub CLI including the code required by license to be redistributed.

During GitHub CLI pull requests, the `lint` workflow will notify users if this information is not updated.

.github/workflows/lint.yml

@@ -5,11 +5,15 @@ on:
       - "**.go"
       - go.mod
       - go.sum
+      - ".github/licenses.tmpl"
+      - "script/licenses*"
   pull_request:
     paths:
       - "**.go"
       - go.mod
       - go.sum
+      - ".github/licenses.tmpl"
+      - "script/licenses*"
 
 permissions:
   contents: read
@@ -56,3 +60,12 @@ jobs:
           bin/golangci-lint run --out-format=colored-line-number --timeout=3m || STATUS=$?
 
           exit $STATUS
+
+      # actions/setup-go does not setup the installed toolchain to be preferred over the system install,
+      # which causes go-licenses to raise "Package ... does not have module info" errors.
+      # for more information, https://github.com/google/go-licenses/issues/244#issuecomment-1885098633
+      - name: Check licenses
+        run: |
+          export GOROOT=$(go env GOROOT)
+          export PATH=${GOROOT}/bin:$PATH
+          ./script/licenses-check