[deps] BRE: Update mariadb Docker tag to v12

[renovate]

This PR contains the following updates:

Package	Update	Change
mariadb	major	10 -> 12

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[bitwarden-bot]

Internal tracking:

• ID: PM-29340
• Link: https://bitwarden.atlassian.net/browse/PM-29340

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 53.64%. Comparing base (3ff5902) to head (c7bc52f).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6704      +/-   ##
==========================================
+ Coverage   53.60%   53.64%   +0.03%     
==========================================
  Files        1921     1926       +5     
  Lines       85650    85720      +70     
  Branches     7687     7687              
==========================================
+ Hits        45911    45981      +70     
  Misses      37967    37967              
  Partials     1772     1772              

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