test_runner: sync ESM exports when mocking timers

[Siddhartha-singh01]

This change ensures that ESM imports of node:timers/promises are correctly mocked when using mock.timers.enable(). This is achieved by calling syncBuiltinESMExports() whenever the mocked timers are toggled or reset.

Fixes: #62081

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[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[mcollina]

lgtm

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.65%. Comparing base (8edeff9) to head (b5ee33c).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #62141    +/-   ##
========================================
  Coverage   89.65%   89.65%            
========================================
  Files         676      676            
  Lines      206342   206546   +204     
  Branches    39531    39553    +22     
========================================
+ Hits       184994   185183   +189     
- Misses      13475    13482     +7     
- Partials     7873     7881     +8     

Files with missing lines	Coverage Δ
lib/internal/test_runner/mock/mock_timers.js	98.69% <100.00%> (+<0.01%)	⬆️

... and 61 files with indirect coverage changes

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