Editor does not understand typescript vue3 single file components

🐛 bug report

Preflight Checklist

• I have read the Contributing Guidelines for this project.
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  adheres to.
• I have searched the issue tracker for an issue that matches the one I want
  to file, without success.

Description of the problem

CodeSandbox seems to think Vue single file components are JSX.
Open components/App.vue of my example and eslint complains about the template tag: adjacent elements must be wrapped in an enclosing tag

This is valid vue: https://vuejs.org/guide/scaling-up/sfc.html

How has this issue affected you? What are you trying to accomplish?

It's impossible to use CodeSandbox to demonstrate Vue typescript issues.

To Reproduce

There is no default Vue+typescript setup according to the recommended guide so we make your own:
Create a Node HTTP sandbox

cd ..
npm init vue@latest // leave everything standard except set typescript and eslint to yes
mv vue-project/* sandbox/
mv vue-project/eslintrc.cjs sandbox/

Restart it and add the following sandbox.config.json:
{ "infiniteLoopProtection": true, "hardReloadOnChange": false, "view": "browser", "container": { "node": "12", "port": 3000, "startScript": "custom" } }

Now open App.vue or HelloWorld.vue and admire the errors

Link to sandbox: https://codesandbox.io/s/vite-vue-3-0r2hgb

Your Environment

Reproduce the report using the linked sandbox, then open components/App.vue and HelloWorld.vue and inspect the reported template errors. Check how the editor identifies these files and compare the behavior with the Vue single-file component guidance linked in the issue. Done means valid Vue TypeScript templates are no longer treated as JSX and the reported ESLint errors are gone.