arrow

GH-34023: [Docs] Version warning about viewing old docs doesn't work for versions >= 10 (#34178)

### Rationale for this change
Due to a bump in number of characters in the major version number (7, 8, 9 etc -> 10) the check for versions in `versionwarning.js` no longer works as expected.

### What changes are included in this PR?
Update of the checks in `versionwarning.js` file.

### Are these changes tested?
Yes, on the apache/arrow-site PR:

- https://github.com/apache/arrow-site/pull/312
- https://arrow.apache.org/docs/10.0/index.html

### Are there any user-facing changes?
No.
* Closes: #34023

Authored-by: Alenka Frim <frim.alenka@gmail.com>
Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>