test: tolerate duplicate watch change events

Allow test-watch-file-shared-dependency to observe multiple watcher
events while still asserting that the expected owner set is reached
exactly once.
Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com>
Assisted-by: openai:gpt-5.5
PR-URL: #63937
Refs: https://github.com/nodejs/node/actions/runs/27462359210/job/81178399610
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>

Author: trivikr

test/parallel/test-watch-file-shared-dependency.mjs

@@ -34,15 +34,22 @@ describe('watch file with shared dependency', () => {
 constcontroller=newAbortController();
 constwatcher=newFilesWatcher({signal: controller.signal});
 
-watcher.on('changed',common.mustCall(({ owners })=>{
-if(owners.size!==2)return;
-
-// If this code is never reached the test times out.
+constonExpectedOwners=common.mustCall(({ owners })=>{
 assert.ok(owners.has(fixturePaths['test.js']));
 assert.ok(owners.has(fixturePaths['test-2.js']));
 controller.abort();
 done();
-}));
+});
+
+functiononChanged({ owners }){
+if(owners.size!==2)return;
+
+// If this code is never reached the test times out.
+watcher.removeListener('changed',onChanged);
+onExpectedOwners({ owners });
+}
+
+watcher.on('changed',onChanged);
 watcher.filterFile(fixturePaths['test.js']);
 watcher.filterFile(fixturePaths['test-2.js']);
 watcher.filterFile(fixturePaths['dependency.js'],fixturePaths['test.js']);