style: enable eslint `no-else-after-return`

[SukkaW]

Enable ESLint's built-in rule no-else-after-return.

And according to the rollup-plugin-size, the emitted dist decreaseds by 4 bytes after the change.

[coveralls]

Pull Request Test Coverage Report for Build 6663522a711ca508c191799a212eb5fb4baedaf8-PR-291

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.831%

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Totals
Change from base Build 55c363f844a20b983d1dcee68be35716b393ee5d:	0.0%
Covered Lines:	270
Relevant Lines:	272

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💛 - Coveralls