Bump MariaDB versions for test - Amazon dropped old ones again (#1921) (#1925)

[PR #1921/a57b5145 backport][stable-7] Bump MariaDB versions for test - Amazon dropped old ones again

This is a backport of PR #1921 as merged into main (a57b514).
SUMMARY
Bump MariaDB versions for test - Amazon dropped old ones again
ISSUE TYPE

Bugfix Pull Request

COMPONENT NAME
rds_instance_upgrade
ADDITIONAL INFORMATION

Reviewed-by: Mark Chappell

Author: patchback[bot]

tests/integration/targets/rds_instance_upgrade/defaults/main.yml

@@ -7,5 +7,5 @@ db_instance_class: db.t3.micro
 allocated_storage: 20
 
 # For mariadb tests
-mariadb_engine_version: 10.5.17
-mariadb_engine_version_2: 10.6.10
+mariadb_engine_version: 10.6.16
+mariadb_engine_version_2: 10.11.6