[CI] Forgejo Actions based release process (squash) MySQL optimization

Refs: https://codeberg.org/forgejo/forgejo/issues/976
(cherry picked from commit b4b8c489e6)

Backport of https://codeberg.org/forgejo/forgejo/pulls/994

(cherry picked from commit 7f2b08d0ad)
(cherry picked from commit bf025db340)

.forgejo/workflows/testing.yml

@@ -62,12 +62,16 @@ jobs:
       image: codeberg.org/forgejo/test_env:main
     services:
       mysql8:
-        image: mysql:8
+        image: mysql:8-debian
         env:
           MYSQL_ALLOW_EMPTY_PASSWORD: yes
           MYSQL_DATABASE: testgitea
         ports:
           - "3306:3306"
+        #
+        # See also https://codeberg.org/forgejo/forgejo/issues/976
+        #
+        cmd: ['mysqld', '--innodb-adaptive-flushing=OFF', '--innodb-buffer-pool-size=4G', '--innodb-log-buffer-size=128M', '--innodb-flush-log-at-trx-commit=0', '--innodb-flush-log-at-timeout=30', '--innodb-flush-method=nosync', '--innodb-fsync-threshold=1000000000']
     steps:
       - uses: https://code.forgejo.org/actions/checkout@v3
       - uses: https://code.forgejo.org/actions/setup-go@v4