tweak(core/rdr3): improve startup meta block logic

[Ehbw]

Goal of this PR

Improve the startup.meta block which was originally introduced in #3318. This patch improves on it by scoping the hook to only the instance where startup.meta existence is checked for.

How is this PR achieving the goal

Remove original hook and replace the call to load platformcrc:/data/startup(.ymt/.meta) with a stub call that forces the call to skip over loading .meta if present.

This PR applies to the following area(s)

FiveM

Successfully tested on

Tested with/without the custom startup.meta file from #3318

Game builds: 1491

Platforms: Windows

Checklist

• Code compiles and has been tested successfully.
• Code explains itself well and/or is documented.
• My commit message explains what the changes do and what they are for.
• No extra compilation warnings are added by these changes.

Fixes issues