mysql-client: fix add authentication plugins in [email protected]

This adds the `-DWITH_AUTHENTICATION_CLIENT_PLUGINS=yes` flag to add
support for older MySQL authentication methods. This support was in the
default build prior to MySQL 9.0, but were dropped with that release.
Closes Homebrew#180498

Formula/m/mysql-client.rb

@@ -48,6 +48,7 @@ def install
       -DINSTALL_INFODIR=share/info
       -DINSTALL_MANDIR=share/man
       -DINSTALL_MYSQLSHAREDIR=share/mysql
+      -DWITH_AUTHENTICATION_CLIENT_PLUGINS=yes
       -DWITH_BOOST=boost
       -DWITH_EDITLINE=system
       -DWITH_FIDO=system