Fix: TypeError in sort_values after dropna

[vineethsaivs]

What do these changes do?

This pull request resolves the issue where sort_values(ignore_index=True) raises a TypeError after using dropna.
The fix ensures proper handling of unknown dimensions by parsing pd.RangeIndex(-1) when the size of the dimension is unknown.

Related issue number

Fixes #2488

Check code requirements

• [x] tests added / passed (if needed)
• [x] Ensure all linting tests pass, see here for how to run them