Is there a term when the final spelling of a word is changed for rhyming purposes?

A Forced Rhyme according to wiktionary

A rhyme that is produced by changing the normal spelling of a word, or by changing the normal structure of a phrase

It covers more than just changing spelling and is generally regarded as bad practice but more so for forcing an inappropriate word than for changing the spelling.

Another example from Twice Times by A. A. Milne:

They lived in a Cave when the weather was cold,
And they Did, and they Didn't Do, what they were told.
Good Bear learnt his Twice Times Three -
But Bad Bear never had his hand-ker-chee
...
There may be a Moral, though some say not;
I think there's a moral, though I don't know what.
But if one gets better, as the other gets wuss,
These Two Little Bears are just like Us.