fix(component-meta): error when signatures is undefined

[Hannesrasmussen]

In certain cases, signatures[0].parameters[0] returns undefined. We need to prevent this from causing an error.

[pkg-pr-new[bot]]

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vue-component-meta

``` pnpm add https://pkg.pr.new/vuejs/language-tools/vue-component-meta@4930 ```

vue-component-type-helpers

``` pnpm add https://pkg.pr.new/vuejs/language-tools/vue-component-type-helpers@4930 ```

@vue/language-core

``` pnpm add https://pkg.pr.new/vuejs/language-tools/@vue/language-core@4930 ```

@vue/language-plugin-pug

``` pnpm add https://pkg.pr.new/vuejs/language-tools/@vue/language-plugin-pug@4930 ```

@vue/language-service

``` pnpm add https://pkg.pr.new/vuejs/language-tools/@vue/language-service@4930 ```

@vue/language-server

``` pnpm add https://pkg.pr.new/vuejs/language-tools/@vue/language-server@4930 ```

vue-tsc

``` pnpm add https://pkg.pr.new/vuejs/language-tools/vue-tsc@4930 ```

@vue/typescript-plugin

``` pnpm add https://pkg.pr.new/vuejs/language-tools/@vue/typescript-plugin@4930 ```

commit: e321381