fix(legacy): import @babel/preset-env

[merceyz]

Description

@vitejs/plugin-legacy specifies that Babel should use @babel/preset-env but doesn't specify where it should resolve it from so Babel defaults to process.cwd(), usually the current project, making it rely on hoisting.

This PR fixes that by dynamically importing @babel/preset-env and passing the result to Babel.

Alternatively one could use the Babel option cwd to make it resolve relative to @vitejs/plugin-legacy or use require.resolve to give Babel an absolute path to the preset.

Additional context

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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 PR Title 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.

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[sapphi-red]

Thank you!

[shalldie]

Release a new version?
Now using pnpm to build will report an error