In bug 1436263, I added a cpp-virtual-final.yml linter to warn about virtual function declarations that included more than one virtual function specifier `virtual`, `final`, or `override`.
I think we should remove this linter now because:
* It's just a style check and doesn't diagnose a real bug. Including more than one virtual function specifier (`virtual`, `final`, or `override`) is harmless and unambiguous, just unnecessary extra code.
* It has caused some engineer frustration because this style check caused their changeset to be backed out of autoland. Backing out and fixing these style issues are not a good use of sheriffs' or engineers' time.
* It doesn't catch all virtual/final/override style issues because:
* It can't analyze virtual function definitions that span multiple lines.
* It doesn't check for `virtual void Foo() override` because there are over 6000 cases already, so our code will never follow this style check consistently.
Differential Revision: https://phabricator.services.mozilla.com/D139454
185d44df61