chore(deps): update devdependency postcss-less to v6

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
postcss-less	^5.0.0 -> ^6.0.0

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Release Notes

shellscape/postcss-less

### [`v6.0.0`](https://togithub.com/shellscape/postcss-less/releases/v6.0.0) [Compare Source](https://togithub.com/shellscape/postcss-less/compare/v5.0.0...v6.0.0) #### Breaking Changes - fix!: add postcss to peerDeps #### Bugfixes - fix: node positional information for files with single-quotes in comments ([#​164](https://togithub.com/shellscape/postcss-less/issues/164)) #### Updates - docs: fix website URL for Less ([#​162](https://togithub.com/shellscape/postcss-less/issues/162))

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Configuration

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[github-actions[bot]]

:tada: This PR is included in version 13.0.23 :tada:

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