Support @container queries (Less.js 4.2.0)

[Gappa]

As reported in #78 (comment).

I made a very rough "fix":

• Gappa@d255214

It kind of works, but hijacks most of the code for media queries, upon which container queries are based, so it makes at least some sense :)

[Krinkle]

We follow upstream, so the implementation will probably wait until after it lands there.

It looks like an upstream issue has already been filed at:
less/less.js#3766

[chrisdeeming]

We follow upstream, so the implementation will probably wait until after it lands there.

Not quickly enough, evidently.

It's disappointing Less.php has stagnated to this point. Meanwhile the PHP port of SCSS has just been rewritten to be compatible with the latest Dart Sass code.

What are the plans for this library going forwards?

[Krinkle]

We've had two dozen releases in 2023 and 2024 to release a fully-compliant Less.js 2.x under Less.php 4.x, and the big Less.php 5.0 release that ports the core parsing, grammar, validation, and formatting of Less.js 3.x/4.x.

At this point porting for Less.js 3.x is finished for Less.php 5.x from our perspective. There are various individual new functions and blocks not yet implemented, such as @container.

Many big projects and companies depend on Less.php. Anyone who needs a specific missing function or keyword in their project is welcome to contribute by submitting a patch that ports over the missing chunk as they see fit.

Those should be easy to port now that the foundations are in place. But, there are a large number of them. We will continue to port small pieces over as-needed. We're not likely to prioritise doing all of them ourselves in the short term.