[cli] Export list of develop PRs to be merged into master (#13944)

* Add developer-only command for exporting the list of PRs associated with a merge to `develop`.

* qmk pytest

* Imports.

* Remove dependencies from requirements file, manually handle.

* Reduce complexity, qmk generate-api taking too long so relying on CI

lib/python/qmk/cli/__init__.py

@@ -47,6 +47,7 @@ subcommands = [
     'qmk.cli.generate.api',
     'qmk.cli.generate.compilation_database',
     'qmk.cli.generate.config_h',
+    'qmk.cli.generate.develop_pr_list',
     'qmk.cli.generate.dfu_header',
     'qmk.cli.generate.docs',
     'qmk.cli.generate.info_json',