fix: use namespace import for vite to support upcoming vite 3.0 esm

[dominikg]

vite 3.0 is going to be esm first 🎉 vitejs/vite#8178

No default export means we have to change a few import vite from 'vite' to prevent errors like this one:
https://github.com/vitejs/vite-ecosystem-ci/runs/6549407184?check_suite_focus=true#step:7:392

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with pnpm test and lint the project with pnpm lint and pnpm check

Changesets

• If your PR makes a change that should be noted in one or more packages' changelogs, generate a changeset by running pnpm changeset and following the prompts. All changesets should be patch until SvelteKit 1.0

[changeset-bot]

🦋 Changeset detected

Latest commit: 3253b09

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@sveltejs/kit	Patch

Not sure what this means? Click here to learn what changesets are.

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

[Rich-Harris]

Nice, this is great news. Is there any reason to prefer named imports over a namespace import? I tend to think vite.build(...) is clearer than build(...) — should we just change import vite to import * as vite instead of changing all the invocations?

[dominikg]

I feel it's a bit more explicit to use the named exports, but the readability is indeed reduced. 🤔 Indifferent about it if there are no other technical benefits in avoiding * imports

[Rich-Harris]

Yeah, there's no technical benefits, it's really just a stylistic preference

[benmccann]

I was going to go with something more like import { createServer, searchForWorkspaceRoot } from 'vite'; but I guess this works too