test: add known_issues test for fs.copyFile()

On macOS, fs.copyFile() may not respect file permissions. There is a PR
for libuv that should fix this, but until it lands and we can either
float a patch or upgrade libuv, have a known_issues test.

Ref: https://github.com/nodejs/node/issues/26936
Ref: https://github.com/libuv/libuv/pull/2233

PR-URL: https://github.com/nodejs/node/pull/26939
Refs: https://github.com/nodejs/node/issues/26936
Refs: https://github.com/libuv/libuv/pull/2233


Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Signed-off-by: Beth Griggs <Bethany.Griggs@uk.ibm.com>