test: remove outdated gettime test #143

[naftalimurgor]

Summary

Hi @wu-emma

Resolves #143

• Removed the stale gettime test.

• The test was originally added to check for 32-bit vs 64-bit time mismatches in the mingw toolchain, but it became obsolete after switching to std::chrono::system_clock 6be319b

• Any future time-related errors should either trigger undefined behavior sanitizers (ubsan) or fail with existing assertions.

• If needed, the test can be reintroduced and extended to cover time handling comprehensively, in coordination with updates to block header timestamp handling (linked to the year 2106 boundary, covered by _test_y2106).

Motivation

• Switch to std::chrono::system_clock : 6be319b
• #31846