[no ci] Add .watchman to .gitignore (pytorch#114718)

Followup after pytorch#114716

TODO: should the old filename be deleted, or it just depends on Atom/VSCode version
Pull Request resolved: pytorch#114718
Approved by: https://github.com/kit1980

.gitignore

@@ -275,6 +275,7 @@ MANIFEST
 
 # Atom/Watchman required file
 .watchmanconfig
+.watchman
 
 # Files generated by CLion
 cmake-build-debug