[Bug Report] Duplicate Tag Creation Clears All Instances of the Tag in element select Component

[BrowLi]

Element UI version

2.15.14

OS/Browsers version

Google Chrome 125.0.6422.142 arm64

Vue version

2.7.16

Reproduction Link

https://codepen.io/lzbghwut-the-typescripter/pen/NWVwdNL

Steps to reproduce

1. Use the select component with the option to create new tags enabled.
2. Add a new tag that already exists in the list.

What is Expected?

When attempting to create a tag that already exists, the original tags should be preserved and no duplicates should be created.

What is actually happening?

All instances of the existing tag are cleared from the list.