TTS_Linux: Fix size_t template issue on OpenBSD by using int consistently

[rfht]

This is a follow-up of #83804. The issue was observed on OpenBSD where compilation failed because of a missing GetTypeInfo<unsigned long> template. Using uint64_t for TTS_Linux::_speech_index_mark() and TTS_Linux::_speech_event() arguments fixes this.

Bugsquad edit:

• Fixes OpenBSD error: conversion from 'const Variant' to 'unsigned long' is ambiguous #74669

[omar-polo]

With this (plus some other "usual" patches like the one for the sndio backed) I'm finally able to compile and run godot on OpenBSD!

I wasn't sure about the cast, but we hit already a similar issue in the embedded copy of embree (https://github.com/openbsd/ports/blob/master/games/godot/patches/patch-thirdparty_embree_common_math_math_h). I guess that having size_t a typedef for unsigned long is not that common?

To be fair I'm still not completely sure why it was failing to build before, I got the cast almost by chance.

[bruvzg]

p_client_id is not used anywhere, so there's no need to pass it to deferred calls. And message ID is limited to int range (in case events it should be always > 0, -1 is used for errors).

[bruvzg]

Please squash the commits, see Pull request workflow for details.

[akien-mga]

Sorry I should have mentioned this earlier: the commit message is incorrect since it's not using uint64_t anymore.
Could you amend it to use something like what I used for the PR title? This makes both the fix and the context more explicit.

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉

[rfht]

actually the third, but still an opportunity to celebrate!
1fe6ad6
204de5e

[YuriSizov]

Cherry-picked for 4.1.4.