test: remove obsolete gettime check

[Aquileo-hub]

Summary

Removes the obsolete gettime unit test that checks whether GetTime() fits in 32 bits.

What changed

• Deleted the old MinGW/Wine gettime compatibility test from src/test/util_tests.cpp.
• Left the modern util_time_GetTime coverage in place for mock time and chrono precision handling.

How tested

• git diff --check
• rg -n "BOOST_AUTO_TEST_CASE\\(gettime\\)|mingw/wine issue #3494|0xffffffff" src/test/util_tests.cpp (no matches)

Not run: src/test/test_BGL --run_test=util_tests, because this checkout does not have a configured build or test binary yet.

Related issue/bounty

Fixes #143.
Also submitted under the public BGL PR bounty hunt (#32/#39) if maintainers consider this change eligible.

Notes

This is intentionally a narrow cleanup PR matching the issue scope.

[Aquileo-hub]

I noticed after opening this that #269 already contains the same focused change for #143. Closing this PR to avoid duplicate review noise. Thanks.