After `@vue/language-server` release 2.0, vue lsp doesn't work. I tried
to support 2.0, but since I'm not familiar with `@vue/language-server`
and `zed` I was unsuccessful. To avoid long-term unavailability, I
temporarily fixed the version to 1.8 until we have 2.0 support.

Release Notes:

- Pinned `@vue/language-server` to version `1.8` until Zed supports
`2.x`. ([#9388](https://github.com/zed-industries/zed/issues/9388) &
[#9329](https://github.com/zed-industries/zed/issues/9329)).

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Co-authored-by: Thorsten Ball <mrnugget@gmail.com>