doc: edit filehandle.close() entry in fs.md

PR-URL: https://github.com/nodejs/node/pull/34782


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Harshitha K P <harshitha014@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>