The HTML sanitizer removes the MathML columnalign attribute

The secure HTML element sanitizer allows the MathML attribute columnsalign, which doesn't exist, instead of columnalign, which aligns the cells in the columns of an mtable. As a consequence, columnalign is removed in restricted HTML cleaning (e.g., HTML macros written by users without script right).

The typo was copied from DOMPurify, which fixed it in a later version.

Steps to reproduce

1. As a user without script right, create a page with:

   {{html}}
   <math xmlns="http://www.w3.org/1998/Math/MathML"><mtable columnalign="left"><mtr><mtd><mn>1</mn></mtd></mtr><mtr><mtd><mn>1000</mn></mtd></mtr></mtable></math>
   {{/html}}
   

Expected: the numbers are left-aligned.
Actual: the columnalign attribute is removed.