Flaky test: GaugeTest.testTimer on Java 25 #1972

Description

GaugeTest.testTimer fails on Java 25 with a timing assertion that's
too tight:

Expecting actual:
  0.101583116
to be close to:
  0.012

at line 91. The test expects ~12ms but the timer measured ~101ms — likely
a scheduling delay on CI.

Suggested fix

Use a more generous tolerance or assert > 0 rather than closeness to
a specific wall-clock duration.