Revert "test: mark test-fs-watch-non-recursive flaky on Windows"

This reverts commit 2a871df.

It has been almost three years since the test was marked flaky. Remove
the unstable designation to see if the problem persists on Windows.

Fixes: nodejs#40728

test/pummel/pummel.status

@@ -7,8 +7,6 @@ prefix pummel
 [true] # This section applies to all platforms
 
 [$system==win32]
-# https://github.com/nodejs/node/issues/40728
-test-fs-watch-non-recursive: PASS,FLAKY
 
 [$system==macos]