chore: bump less to 4.2.2

[Laffery]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/NG-ZORRO/ng-zorro-antd/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Application (the showcase website) / infrastructure changes
• Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

• bump postcss to 8.5.1
• bump less-plugin-clean-css to 1.6.0

Does this PR introduce a breaking change?

• Yes
• No

Other information

[zorro-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.93%. Comparing base (2276eaa) to head (507fcf9).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8992      +/-   ##
==========================================
- Coverage   91.93%   91.93%   -0.01%     
==========================================
  Files         555      555              
  Lines       19712    19712              
  Branches     2946     2946              
==========================================
- Hits        18123    18122       -1     
- Misses       1263     1264       +1     
  Partials      326      326              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.