ci: adapt tests for MySQL v9

[wellwelwel]

Some tests statically check for MySQL Server v8, where otherwise they understood it as v5.

These adjustments ensure that the tests dynamically check for MySQL Server versions.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.34%. Comparing base (f23c0f1) to head (c2be887).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2834   +/-   ##
=======================================
  Coverage   90.34%   90.34%           
=======================================
  Files          71       71           
  Lines       15749    15749           
  Branches     1350     1351    +1     
=======================================
  Hits        14228    14228           
  Misses       1521     1521           

Flag	Coverage Δ
compression-0	90.34% <ø> (ø)
compression-1	90.34% <ø> (ø)
tls-0	89.86% <ø> (ø)
tls-1	90.14% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.