Clamp tab_size setting between 1 and 16 (#17882)

Release Notes:

- Changed `tab_size` setting to require values be between 1 and 16
(inclusive).


### jetbrains settings 

#### Max value

![image](https://github.com/user-attachments/assets/54b772fd-e670-4d77-b3e9-757b08659f55)

When the maximum value is exceeded, the configuration box turns red to
remind the user


![image](https://github.com/user-attachments/assets/fcdb6313-be97-4528-b654-5900bcaeafec)

If the user still saves, jetbrains does not process it and resets it to
the system default value of 4

<img width="700" alt="image"
src="https://github.com/user-attachments/assets/a76b1cba-d23f-4a32-95ee-f05d208ca186">

Without restrictions, I feel not good. Here is a random setting of a
relatively large value



https://github.com/user-attachments/assets/c3bdf262-ba08-4bc2-996a-5ad2a37c567f

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/language/src/language_settings.rs

@@ -1027,6 +1027,10 @@ fn merge_settings(settings: &mut LanguageSettings, src: &LanguageSettingsContent
     }
 
     merge(&mut settings.tab_size, src.tab_size);
+    settings.tab_size = settings
+        .tab_size
+        .clamp(NonZeroU32::new(1).unwrap(), NonZeroU32::new(16).unwrap());
+
     merge(&mut settings.hard_tabs, src.hard_tabs);
     merge(&mut settings.soft_wrap, src.soft_wrap);
     merge(&mut settings.use_autoclose, src.use_autoclose);