write redirects for prerendered pages with trailing slashes

[Rich-Harris]

fixes #7725. The prerendered page wasn't being served because the overrides config in .vercel/output/config.json can't have a path value with a trailing slash. To get the correct behaviour we have to remove the trailing slash, and also add two entries to the routes config for each prerendered page:

{ "src": "/the-path/", "dest": "/the-path" },
{ "src": "/the-path", "status": 308, "headers": { "Location": "/the-path/" } }

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Latest commit: b9142f6

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@sveltejs/adapter-vercel	Patch

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[Conduitry]

Is it intended to also be logging this to stdout, or was this just for debugging? Will that make things too noisy?

[Rich-Harris]

it is not intended. oops