chore: clean codes

[cipchk]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/ng-alain/delon/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?

Does this PR introduce a breaking change?

[ ] Yes
[ ] No

Other information

[ng-alain-bot]

Preview is ready!

[codecov]

Codecov Report

Merging #1608 (ea4af9c) into master (2ecc28b) will decrease coverage by 0.01%.
The diff coverage is n/a.

❗ Current head ea4af9c differs from pull request most recent head 9a00065. Consider uploading reports for the commit 9a00065 to get more accurate results

@@            Coverage Diff             @@
##           master    #1608      +/-   ##
==========================================
- Coverage   95.54%   95.53%   -0.01%     
==========================================
  Files         276      276              
  Lines        8500     8497       -3     
  Branches     1660     1660              
==========================================
- Hits         8121     8118       -3     
  Misses        317      317              
  Partials       62       62              

Impacted Files	Coverage Δ
packages/abc/date-picker/range.directive.ts	89.15% <ø> (-0.38%)	⬇️