append function redirects after copying existing redirects - fixes #4722

[Rich-Harris]

Closes #4722 — fixes a bug introduced in #4657. If you have an existing _redirects file, it needs to be copied before lambdas are generated, not after.

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 pnpx changeset and following the prompts. All changesets should be patch until SvelteKit 1.0

[changeset-bot]

🦋 Changeset detected

Latest commit: 0c08e1d

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

This PR includes changesets to release 1 package

Name	Type
@sveltejs/adapter-netlify	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

[benmccann]

I don't know if it's worth adding a comment explaining why it needs to be done before?

[Rich-Harris]

done

[nosovk]

It seems that in latest version issue still exists.

/static/_redirects

+ /contacts /#contacts 302

Results in a link https://realliveslots.com/contacts
It means that _redirects file was parsed and accepted by cloudflare pages, but...

As you can see, road defined in `_redirects` still handled by worker script, not by CloudFlare _redirects mechanizm.