Skip test_new_mode if the mw version < 1.25wmf4

Skips test_new_mode for sites using mw version '1.25wmf3' or before
as in MW version 1.25wmf4 a new method for obtaining API parameter
information was added and the old method was deprecated.

Bug: T77966
Change-Id: I13bb53c04c6a49828b99f268ba7fed5e41c0f9bc
Merge "Skip test_new_mode if the mw version < 1.25wmf4"