test: give windows file watcher more time

[sunng87]

I hereby agree to the terms of the GreptimeDB CLA.

Refer to a related PR or issue link (optional)

What's changed and what's your intention?

Give file change detection test on windows more time.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR requires documentation updates.

[tisonkun]

I may prefer to conditionally define the timeout constant ...

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.34%. Comparing base (66aa08d) to head (11fad61).
Report is 44 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3953      +/-   ##
==========================================
- Coverage   86.03%   85.34%   -0.69%     
==========================================
  Files         955      972      +17     
  Lines      163870   166846    +2976     
==========================================
+ Hits       140990   142403    +1413     
- Misses      22880    24443    +1563     

[killme2008]

LGTM