src: tolerate EPERM returned from tcsetattr

macOS app sandbox makes tcsetattr return EPERM. The CHECK_EQ(0, err)
here would fail when a sandboxed Node.js process is exiting. This commit
fixes this issue.

* test: add test for running in macOS app sandbox

Bare-bone command-line executables cannot run directly in the app sandbox.
To test that Node.js is able to run in the sandbox (and to test the fix in
317621b4a12562eb75055a67bb2c5556f53fe017), this commit creates a typical
Cocoa app bundle, puts the node executable in it and calles Apple's codesign
command to enable sandbox.

* test: use process.execPath to get path of testing node

PR-URL: https://github.com/nodejs/node/pull/33944


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>