worker: remove file extension check

Fixes: https://github.com/nodejs/node/issues/39124

PR-URL: https://github.com/nodejs/node/pull/39788


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>