change debian packaging to not run mariadb-upgrade at the same time as anything

Spider, CS and potentially other plugins install udf functions, stored functions and stored procedures. The mysql_upgrade is changes the format of mysql.func, proc and other system tables related to those operations. Evidenced by:

• MDEV-14622 spider / mysql_upgrade deadlock - drop procedure / alter table proc
• MDEV-27107 spider / mysql_upgrade deadlock - create udf function / alter table func

Including but not limited to:

• User connections
• Installation of other packages (e.g. spider, CS) and their plugins

A solution part of packaging might look like:

mysql_upgrade --check-if-upgrade-is-needed

followed by a temporary start of the server (additional options - https://jira.mariadb.org/browse/MDEV-27068?focusedCommentId=207708&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-207708), maybe put these in a [mariadb.upgrade] group the in the configuration file and use --defaults-group-suffix=.upgrade.

followed by mysql_upgrade --upgrade-system-tables