Update `Locale` signatures

[devnix]

I'm not sure about documenting all optional parameters of Locale::composeLocale() as it has no effect when introducing non-documented parameters to the function, but I've reviewed all the functions, even the undocumented ones and AFAIK these are the correct signatures 😊

[devnix]

Not sure why this is failing: https://github.com/phpstan/phpstan-src/actions/runs/7568063545/job/20608638825?pr=2880

[ondrejmirtes]

That build failure is not the fault of this PR.

[ondrejmirtes]

Also please get rid of the merge commit, the history should be linear (use rebase instead).

[devnix]

I think this should do it 😄

[ondrejmirtes]

Thank you.

[lazka]

Did this fix https://github.com/phpstan/phpstan/issues/7855 ?