MariaDB 10.6.4 (32-bit)

What's new in this version:

InnoDB:
- InnoDB no longer acquires advisory file locks by default
- Encryption: Automatically disable key rotation checks for file_key_management plugin
- Some fixes from MySQL 5.7.35
- Fixed scrubbing on AIX
- buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED

Optimizer:
- A query that uses ORDER BY .. LIMIT clause and "Range checked for each record optimization" could produce incorrect results under some circumstances
- Queries that have more than 32 equality conditions comparing columns of different tables ("tableX.colX=tableY.colY) could cause a stack overrun in the query optimizer
- "Condition pushdown into derived table" optimization cannot be applied if the expression being pushed refers to a derived table column which is computed from expression that has a stored function call, @session variable reference, or other similar construct. The fix for MDEV-25969 makes it so that only the problematic part of the condition is not pushed. The rest of the condition is now pushed.
- A query with window function on the left side of the subquery could cause a crash.
- Fixed the issue fixed in MySQL Bug #76803: DML or locking SELECT statements that use outer joins could produce this warning in the error log: [ERROR] InnoDB: Unlock row could not find a 3 mode lock on the record.

Packaging & Misc:
- As per the MariaDB Deprecation Policy, this will be the last release of MariaDB 10.6 for Ubuntu 20.10 Groovy
- Debian 11 Bullseye repositories added
- Galera updated to 26.4.9
- Linux on IBM Z (s390x) architecture added with releases on Ubuntu-20.04 Focal

Security:
Fixes for the following security vulnerabilities:
- CVE-2021-2372
- CVE-2021-2389