fix: Revert breaking change for incoming token creation reqs (#2084)

## What

This change reverts the spec change to create-api-token-schema that
was introduced in 97c2b3c089

That commit changed the endpoint from allowing any string to only
allowing strings that match the values of the ApiTokenType value.

## Why

Because we already validate this on the backend, I didn't think it
would break anything. However, because OpenAPI enums are case
sensitive (and do not currently support anything else), it _did_ break
the API. ([stack overflow post that explains how this
works](https://stackoverflow.com/questions/60772786/case-insensitive-string-parameter-in-schema-of-openapi))

## Of note

This should have been caught by the tests, but it didn't show up until
it was merged to the main branch. I think it might be worth looking
into how we do the PR testing.

src/lib/openapi/spec/create-api-token-schema.ts

@@ -30,7 +30,7 @@ export const createApiTokenSchema = {
         },
         type: {
             type: 'string',
-            enum: Object.values(ApiTokenType),
+            description: `One of ${Object.values(ApiTokenType).join(', ')}`,
         },
         environment: {
             type: 'string',