Add test coverage for text_* Test::Mojo methods

[charliesheh]

Adds coverage for the following Test::Mojo methods in t/test/mojo.t:

• text_is
• text_isnt
• text_like
• text_unlike

The new tests validate:

• exact text matching
• negative text matching
• regex similarity matching
• regex negative matching
• custom description handling

This improves Test::Mojo method coverage consistency alongside the existing attr_* and content_* tests.

[kraih]

Patch doesn't do what you describe it does.