[5.3] Deprecate unused language strings mod_stats_admin

[brianteeman]

This PR deprecates various language strings that are not used in the module

code review.

Thanks to @leeroy1821

Pull Request for Issue #44252

Testing Instructions

code review

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed

[Quy]

I have tested this item ✅ successfully on 86a450e

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[alikon]

I have tested this item ✅ successfully on 86a450e

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/44271.}

[alikon]

RTC

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[brianteeman]

thanks