enable and fix no-unused-vars and no-async-promise-executor

[anatawa12]

What

タイトルの通り。
(Port from #16983)

Why

lint を修正するため。no-async-promise-executorに関してはエラーハンドリングの穴を作ることになり、最悪unhandled promise rejectionでプロセスクラッシュを引き起こすので修正。

Additional info (optional)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests

[codecov]

Codecov Report

❌ Patch coverage is 66.83673% with 65 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.26%. Comparing base (f6fc78f) to head (ef0edfb).
⚠️ Report is 8 commits behind head on develop.

Files with missing lines	Patch %	Lines
packages/frontend/src/utility/drive.ts	0.00%	6 Missing ⚠️
packages/backend/src/core/UserSuspendService.ts	0.00%	3 Missing ⚠️
packages/frontend/src/os.ts	0.00%	3 Missing ⚠️
packages/frontend/src/plugin.ts	0.00%	3 Missing ⚠️
packages/frontend/src/utility/paginator.ts	0.00%	3 Missing ⚠️
packages/backend/src/core/MfmService.ts	50.00%	2 Missing ⚠️
packages/backend/src/core/NoteDraftService.ts	0.00%	2 Missing ⚠️
...ges/backend/src/core/entities/MetaEntityService.ts	0.00%	2 Missing ⚠️
...end/src/core/entities/NoteReactionEntityService.ts	0.00%	2 Missing ⚠️
...e/processors/ExportCustomEmojisProcessorService.ts	0.00%	2 Missing ⚠️
... and 35 more

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #17070      +/-   ##
===========================================
+ Coverage    63.19%   63.26%   +0.06%     
===========================================
  Files         1154     1156       +2     
  Lines       115410   115605     +195     
  Branches      8023     8072      +49     
===========================================
+ Hits         72939    73139     +200     
- Misses       40305    40318      +13     
+ Partials      2166     2148      -18     

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[github-actions]

Backend Memory Usage Comparison

Metric	base	head	Diff
RSS	321.57 MB	313.89 MB	-7.67 MB (-2.38%)

See workflow logs for details

[github-actions]

このPRによるapi.jsonの差分
差分はありません。
Get diff files from Workflow Page

[syuilo]

🙏🏻