fix: type errors with strictTemplates

[hsuanxyz]

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?

[x] 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: #5171

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

[zorro-bot]

This preview will be available after the AzureCI is passed.

[codecov]

Codecov Report

Merging #5265 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #5265   +/-   ##
=======================================
  Coverage   91.32%   91.33%           
=======================================
  Files         551      551           
  Lines       13908    13908           
  Branches     2099     2099           
=======================================
+ Hits        12702    12703    +1     
  Misses        713      713           
+ Partials      493      492    -1     

Impacted Files	Coverage Δ
components/calendar/calendar.component.ts	100.00% <ø> (ø)
components/cascader/typings.ts	100.00% <ø> (ø)
...onents/descriptions/descriptions-item.component.ts	100.00% <ø> (ø)
components/cascader/cascader.component.ts	95.42% <100.00%> (ø)
components/core/util/convert.ts	85.71% <100.00%> (ø)
components/date-picker/date-picker.component.ts	96.52% <100.00%> (ø)
...mponents/date-picker/date-range-popup.component.ts	90.65% <100.00%> (ø)
components/date-picker/inner-popup.component.ts	89.83% <100.00%> (ø)
...omponents/date-picker/lib/abstract-panel-header.ts	88.63% <100.00%> (ø)
components/date-picker/lib/abstract-table.ts	89.28% <100.00%> (ø)
... and 11 more

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[wenqi73]

LGTM

[wzhudev]

这里应该看一下 IDiffEditor，我之后来处理一下

[wzhudev]

LGTM on my part