build!: remove node v12 support

[Shinigami92]

Description

Fully remove support for node v12

Additional context

According to https://kangax.github.io/compat-table/es2016plus/#node14_6 I switched also to at least v14.6.0
If I'm correct, we also can target ES2020 from now on 🎉

For upgrade to node v18 see #7812

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[jeffydc]

This PR will fix #5843 and #5841

[bluwy]

We may also want to update the versions in the docs like in #5843 (here and here)

[Shinigami92]

We may also want to update the versions in the docs like in #5843 (here and here)

done

[sapphi-red]

Maybe it is out of scope of this PR, but you might forgot to change build settings?
Examples

• vite/packages/vite/rollup.config.js

  Line 131 in ef903d6

  target: 'es2019',

• vite/packages/plugin-vue/tsconfig.json

  Line 6 in ef903d6

  "target": "ES2019",

• vite/packages/plugin-vue/package.json

  Line 16 in ef903d6

  "build-bundle": "esbuild src/index.ts --bundle --platform=node --target=node12 --external:@vue/compiler-sfc --external:vue/compiler-sfc --external:vite --outfile=dist/index.js & npm run patch-dist",

[Shinigami92]

Maybe it is out of scope of this PR, but you might forgot to change build settings? Examples

• vite/packages/vite/rollup.config.js

  Line 131 in ef903d6

  target: 'es2019',

• vite/packages/plugin-vue/tsconfig.json

  Line 6 in ef903d6

  "target": "ES2019",

• vite/packages/plugin-vue/package.json

  Line 16 in ef903d6

  "build-bundle": "esbuild src/index.ts --bundle --platform=node --target=node12 --external:@vue/compiler-sfc --external:vue/compiler-sfc --external:vite --outfile=dist/index.js & npm run patch-dist",

I think we should do this in a separate PR 🤔