Revert "fix(etag): fallback if res.clone() is not supported (#4198)"

[yusukebe]

This reverts commit 548d73f.

The author should do the following, if applicable

• Add tests
• Run tests
• bun run format:fix && bun run lint:fix to format the code
• Add TSDoc/JSDoc to document the code

[github-actions]

Bundle size check

	main (548d73f)	#4200 (20650f0)	+/-
Bundle Size (B)	19,027B	19,027B	0B
Bundle Size (KB)	18.58K	18.58K	0K

Compiler Diagnostics (typescript-go)

	main (548d73f)	#4200 (20650f0)	+/-
Files	231	231	0
Lines	106,340	106,340	0
Identifiers	106,183	106,183	0
Symbols	371,551	371,551	0
Types	293,004	293,004	0
Instantiations	3,568,489	3,568,489	0
Memory used	229,648K	229,774K	126K
Memory allocs	10,003,624	10,003,698	74
Parse time	0.07s	0.098s	0.028s
Bind time	0.018s	0.037s	0.019s
Check time	1.406s	1.483s	0.077s
Emit time	0s	0s	0s
Total time	1.495s	1.629s	0.134s

---

Reported by octocov

[github-actions]

Bundle size check

	main (548d73f)	#4200 (20650f0)	+/-
Bundle Size (B)	19,027B	19,027B	0B
Bundle Size (KB)	18.58K	18.58K	0K

Compiler Diagnostics (tsc)

	main (548d73f)	#4200 (20650f0)	+/-
Files	261	261	0
Lines	116,441	116,441	0
Identifiers	114,443	114,443	0
Symbols	259,900	259,900	0
Types	162,567	162,567	0
Instantiations	3,039,293	3,039,293	0
Memory used	273,277K	268,752K	-4,525K
I/O read	0.02s	0.02s	0s
I/O write	0s	0s	0s
Parse time	0.66s	0.65s	-0.01s
Bind time	0.28s	0.29s	0.01s
Check time	3.76s	4.05s	0.29s
Emit time	0s	0s	0s
Total time	4.71s	4.99s	0.28s

---

Reported by octocov

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.35%. Comparing base (548d73f) to head (a488aea).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4200      +/-   ##
==========================================
+ Coverage   91.32%   91.35%   +0.02%     
==========================================
  Files         168      168              
  Lines       10802    10707      -95     
  Branches     3073     3115      +42     
==========================================
- Hits         9865     9781      -84     
+ Misses        936      925      -11     
  Partials        1        1              

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