For loop with negative step: false positive

### How are you using the lua-language-server?

NeoVim

### Which OS are you using?

Windows WSL

### What is the issue affecting?

Diagnostics/Syntax Checking

### Expected Behaviour

Warning shouldn't be displayed

### Actual Behaviour

Warning is displayed

### Reproduction steps

```lua
local r = 1
for x = -r, 1 do
print(x)
end
```

### Additional Notes

Tested on 3.13.2.

### Log File

I am using nvim + mason, and it does not save any logs even with command line arguments.

Run the provided Lua snippet in LuaLS 3.13.2 through the reported Neovim setup and confirm the diagnostic under Diagnostics/Syntax Checking. Trace how numeric for loops are analyzed, then verify that this valid loop no longer produces the warning.

Written by the indexing model from the issue text.