Update dependency less to v4

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
less (source)	3.13.0 -> 4.0.0

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Release Notes

less/less.js

v4.0.0

Compare Source

• #​3573 v4.0.0 (#​3573) (@​matthew-dean)

v3.13.1

Compare Source

• #​3575 Fixes #​3574 (#​3575) (@​matthew-dean)

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[diox]

This seems to be the cause of this error:
ParseError: Unrecognized input. Possibly missing '(' in mixin call. in /code/static/css/impala/typography.less on line 121, column 9:

Not sure if this has real implications yet.

[eviljeff]

🙄 I guess this is a silent error (can we make it fail in CI at least?).

[eviljeff]

looks like less/less.js@67ce103 "Require parens after mixin call"

[eviljeff]

it'd be nice if the changelog for a breaking major release wasn't just a link to a PR that's a bunch of random commits without explanation (or even any issues linked) to explain the reasoning behind the changes.

[diox]

🙄 I guess this is a silent error (can we make it fail in CI at least?).

I'm guessing this is silent because compress_assets is just ignoring it - when it calls less, it should check the return value and abort/raise when the return value of the command is not right - hopefully there is a different return value in that case...