fix: select inner input reduce 2px when selected length equal 0

[youpinyao]

fix: select inner input reduce 2px when selected length equal 0

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👋 @youpinyao, seems like this is your first time contribution to element-plus.

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[github-actions]

[github-actions]

Hello @youpinyao, thank you for contributing to element-plus, please see our guideline to see how to make contribution

[chenxch]

@youpinyao Sorry, it was my oversight, didn't see your pr, did an extra fix. You can take a look at #8423 repair plan and look forward to your next pr, I'm very sorry.

[xiaoxian521]

Hey, thank you very much for your contribution, but here are some conflicts that need to be solved by you. We can continue to review the code after solving. One thing to remind is that if the conflicts is still not resolved after 10 days, sorry, we will close this pr ❤️