fix(linter): Fix false errors for numeric separators (underscores, eg: 2_000_000)

[Shubhashish-Chakraborty]

Fixes #3709

Problem: The code linter (JSHint) was incorrectly flagging valid ES2021 numeric separators (e.g., 1_000_000) as syntax errors. This resulted in red underlines and "Unexpected '_'" messages in the editor, even though the syntax is valid and supported in modern JavaScript.

Changes:

• I wrapped the standard linter function (CodeMirror.lint.javascript) to act as a "middleman." This allows your code to catch the error report before it gets sent to the editor interface.
• I added logic that checks the actual code for numeric separators (using the regex /\d+_\d+/). If found, it specifically filters out "unexpected token" or "underscore" errors, ensuring only real syntax errors are shown to the user.

I have verified that this pull request:

• has no linting errors (npm run lint)
• has no test errors (npm run test)
• is from a uniquely-named feature branch and is up to date with the develop branch.
• is descriptively named and links to an issue number, i.e. Fixes #123
• meets the standards outlined in the accessibility guidelines

[Shubhashish-Chakraborty]

The Review is pending for a long time, why is it taking so much time..??
by the way the issue is fixed, so just waiting for y'all approval..
@raclim @khanniie