Patch release 4.2.1 with fix for issue number 4235

[puckowski]

A fix for issue 4235 (#4235) has been merged into master.

See PR 4237: #4237

While CSS Container Style Queries are not yet broadly supported (https://caniuse.com/css-container-queries-style#:~:text=Style%20queries%20in%20Container%20Queries,the%20contents%20of%20that%20container.), some users of Less.js may find their userbase and codebase could benefit from support for the feature.

Right now trying to use CSS Container Style Queries on Less.js version 4.2.0 produces incorrect CSS.

Could we prepare a patch release (4.2.1) with the fix for CSS Container Style Queries?