Fix valkey test_save

[rukai]

On a sufficiently fast machine these tests fail since the timestamps are equal.
The fix is to use >= comparison to allow the equal case to also pass the test.

[codspeed-hq]

CodSpeed Performance Report

Merging #1838 will not alter performance

_{Comparing rukai:fix_valkey_test_save (cf1d4f2) with main (de3658e)}

Summary

✅ 38 untouched benchmarks