Add RU language for local transltor.

[lydex-dev]

Is your feature request related to a problem? Please describe. No, except that I have to use a third party extension.

Describe the solution you'd like Add Russian language, at least from the new ESR branch (140, which will be released in June).

Describe alternatives you've considered Only third-party extensions

Additional context This was added in Firefox 135 (mainline).