v2.21.1

🐛 Bug Fixes

• b5326c3 - use ApiKeyAuth instead of BearerAuth (PR #3684 by @rpcross)
• 5680142 - use mailmanclient for mailman API instead of requests (PR #3685 by @rpcross)
• dbd1eb0 - turn off spellcheck for search inputs. Fixes #3688 (PR #3689 by @rpcross)