action: delete clean-cache

[Desiki-high]

Relevant Issue (if applicable)

N/A

Details

Since #1498, we will never save caches in pr, so we don't need clean-cache.

Types of changes

What types of changes does your PullRequest introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

Go over all the following points, and put an x in all the boxes that apply.

• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #1503 (d1a0d17) into master (a3e60c0) will decrease coverage by 0.01%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1503      +/-   ##
==========================================
- Coverage   62.74%   62.73%   -0.01%     
==========================================
  Files         129      129              
  Lines       44158    44158              
  Branches    44158    44158              
==========================================
- Hits        27705    27702       -3     
  Misses      15088    15088              
- Partials     1365     1368       +3     

see 2 files with indirect coverage changes