refactor: ♻️ 4.1 support

[KANAjetzt]

supersedes #441

Original PR Description:

Changes made:

• Removed typed for...in variables because Godot 4.1 doesn't support them
• Downgraded some .tres to format version 3, because format version 4 isn't supported in Godot 4.1
• Used custom function instead of type_string, which does not exist in Godot 4.1

I did a proper test in Godot 4.1 and encountered no issues.

I did not test in later versions of Godot, but I don't think there's anything here that could break.

Todos

• _ModLoaderModHookPreProcessor.fix_method_super() erases everything after the function body, leaving only the first function in a script.
  

  godot-mod-loader/addons/mod_loader/internal/mod_hook_preprocessor.gd

  Lines 313 to 317 in 7b36e32

  	func fix_method_super(method_name: String, func_body: RegExMatch, text: String) -> String:
  	return regex_super_call.sub(
  	text, "super.%s" % method_name,
  	true, func_body.get_start(), func_body.get_end()
  	)

• Change the ´.fix_method_super()` fix to use Regex.sub again, and just add the rest of the string back after sub replaced the super calls.

Todos

• Godot 4.2 Test (Tested with Dome Keeper)
• Godot 4.3 Test (Tested with flashit)

[Qubus0]

looks good, ty.
the resources might get annoying since they will always want to be saved in the newer format version.
we might also want to consider an engine version test that just runs --check-only on each of our scripts for every version we want to support in order to avoid accidentally using things like typed loop variables.