test: relax timer check in test-report-uv-handles.js

The underlying JavaScript runtime may schedule tasks at its discretion
so there may be more timer handles than the one created by the test.

PR-URL: https://github.com/nodejs/node/pull/26434


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>