chore: drop direct deps on acorn and @sveltejs/acorn-typescript

[manuel3108]

Relates #828

This is more or less only a maintainability change. svelte under the hood still uses acorn and @sveltejs/acorn-typescript, but this makes us independent of this implementation detail.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 324874b

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[pkg-pr-new]

Open in StackBlitz

npx https://pkg.pr.new/sveltejs/cli/svelte-migrate@865

npx https://pkg.pr.new/sveltejs/cli/sv@865

commit: 324874b

[jycouet]

LGTM