`:` are not typed checked properly

[Rathoz]

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows

What is the issue affecting?

Type Checking

Reproduction steps

---@param a number|string
function Foo.Bar(a)
	return a:lower() -- Should warn as the code will error on a number input
end

Additional Notes

https://github.com/LuaLS/lua-language-server/issues/2708#issuecomment-2337046169

Log File

No response