website: package.json: copy over schema for npm run watch (#13543)

* root: Makefile: copy over schema for website-watch

`make website-watch` will fail with the following error if the schema.yml file is not present in the website's static directory. This was tested on a branch up to date with main with the schema file I copied over removed.
```
➜  authentik git:(sdko/integrations-all/migr-to-wizard) ✗ w
cd website && npm run watch

> @goauthentik/website-docs@0.0.0 watch
> docusaurus gen-api-docs all && docusaurus start

(node:102678) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
Loading of api failed for "/home/d/Code/authentik/website/static/schema.yml"

[ERROR] [Error: ENOENT: no such file or directory, lstat '/home/d/Code/authentik/website/static/schema.yml'] {
  errno: -2,
  code: 'ENOENT',
  syscall: 'lstat',
  path: '/home/d/Code/authentik/website/static/schema.yml'
}
[INFO] Docusaurus version: 3.7.0
Node version: v23.6.1
make: *** [Makefile:233: website-watch] Error 1
```

We should copy over the schema each time in case it changes. Adding it to this Makefile instruction as [official docs](https://docs.goauthentik.io/docs/developer-docs/setup/website-dev-environment) tell users to run `make website-install` which simply `npm ci`s, then this...

Signed-off-by: Dominic R <dominic@sdko.org>

* tabs?

Signed-off-by: Dominic R <dominic@sdko.org>

* Update Makefile

Signed-off-by: Dominic R <dominic@sdko.org>

* Update package.json

Signed-off-by: Dominic R <dominic@sdko.org>

* Update package.json

Signed-off-by: Dominic R <dominic@sdko.org>

---------

Signed-off-by: Dominic R <dominic@sdko.org>

website/package.json

@@ -14,7 +14,7 @@
         "serve": "docusaurus serve",
         "swizzle": "docusaurus swizzle",
         "test": "node --test",
-        "watch": "docusaurus gen-api-docs all && docusaurus start"
+        "watch": "cp -f ../schema.yml ./static/schema.yml && docusaurus gen-api-docs all && docusaurus start"
     },
     "dependencies": {
         "semver": "^7.7.1",