Check license generation for every PR to avoid license-less crate additions (#10033)

Also fix `anthropic` crate and make it AGPL-licensed, as it's used in
the AGPL-licensed collab part only.

Release Notes:

- N/A

.github/workflows/ci.yml

@@ -54,6 +54,9 @@ jobs:
       - name: Check unused dependencies
         uses: bnjbvr/cargo-machete@main
 
+      - name: Check license generation
+        run: script/generate-licenses /tmp/zed_licenses_output
+
       - name: Ensure fresh merge
         shell: bash -euxo pipefail {0}
         run: |