Disable the crash handler if execinfo=no scons option is set

[LinuxUserGD]

Because the crash handler is not enabled in template_release build mode, libexecinfo is not always required on non-glibc systems.

On Gentoo Linux, libexecinfo is not packaged and therefore scons is patched to disable execinfo=yes by default:
https://gitweb.gentoo.org/repo/gentoo.git/tree/dev-games/godot/files/godot-4.0_rc2-musl.patch

The PR changes the default value of the Scons option execinfo to None so libexecinfo will not be implicitely linked if the Scons option execinfo=no is specified.

See #57193

[Calinou]

Because the crash handler is not enabled in template_release build mode

We should really look into changing that, as this behavior is inconsistent depending on the platform and users ought to be able to investigate crashes with release export templates too. Otherwise, reporting bugs becomes much harder for players of your game. #61906 is the first step towards improving this, but it's also designed to work in exported projects.

[Riteo]

So, I do agree on having the crash handler in the release template too but, in the meanwhile, wouldn't it make sense to consider it still? The wording above by @Calinou seems to block it, but I might be mistaken.

[akien-mga]

Looks good to me.

[akien-mga]

Thanks!

[Riteo]

Oops, forgot to send the review, my bad :P

Just saying that from my part it looks fine! I always like improvements for "non-mainstream" setups!