fix: delete combination check

[miurahr]

Checking Qt version and modules combination become unfeasible, because release of new versions are frequent.
Also aqtinstall now have a feature to list versions, modules, archives.

This is a proposal of removal of combination check feature.

• Delete combinations.json and relevant CI script to update it
• Delete feature to print warning with check combinations
• Delete Settings class methods and field to examine combination database
• Remove tests to check combinations
• Update expectation of tests, which expect showing warn.

[pzhlkj6612]

Will close:

• Topic: deprecate offline parameter validation and "combinations.json" #748
• [Bug]: CI failed: combination detection  #807

.

[pzhlkj6612]

lgtm