Update mysql

Changes:

- docker-library/mysql@b06a707: Merge pull request docker-library/mysql#821 from infosiftr/signed-by
- docker-library/mysql@4afbe06: Switch from apt-key/trusted.gpg(.d) to signed-by
- docker-library/mysql@0bd6d4c: Fix .gitattributes

Author: docker-library-bot

library/mysql

@@ -5,11 +5,11 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
 GitRepo: https://github.com/docker-library/mysql.git
 
 Tags: 8.0.28, 8.0, 8, latest
-GitCommit: aa600026fe54b1fa6b2a7ac80ffbb466618fcabf
+GitCommit: 4afbe061ef1dc5f5fea3971ad9fcf8f0c796b91c
 Directory: 8.0
 File: Dockerfile.debian
 
 Tags: 5.7.37, 5.7, 5
-GitCommit: aa600026fe54b1fa6b2a7ac80ffbb466618fcabf
+GitCommit: 4afbe061ef1dc5f5fea3971ad9fcf8f0c796b91c
 Directory: 5.7
 File: Dockerfile.debian