fix(provider): Add scope string array type

[Liam-Tait]

Reasoning 💡

Documentation and code already handles string[] for scope, this pr updates the typescript types to match the current functionality and usage.

See https://next-auth.js.org/configuration/providers#options for current docs

Checklist 🧢

• Documentation
• Tests
• Ready to be merged

Documentation is already up to date
I don't think any tests are required.
This should be ready to be merged as soon as it is reviewed

Affected issues 🎟

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[ubbe-xyz]

We use the Node oauth client for sign-in with providers, as you suggested, it does accept string[] for scope 👍🏽

[codecov-commenter]

Codecov Report

Merging #2511 (ec0377e) into main (be74dd0) will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##            main   #2511   +/-   ##
=====================================
  Coverage   9.90%   9.90%           
=====================================
  Files         84      84           
  Lines       1403    1403           
  Branches     395     395           
=====================================
  Hits         139     139           
  Misses      1038    1038           
  Partials     226     226           

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[balazsorban44]

@lluia
The current package does support it, but the one in v4 won't by default:

https://github.com/panva/node-openid-client/blob/772306cc82b72ace9361f4a945249a5c35a8f921/types/index.d.ts#L138

The question is what should we do?

1. Merge this PR and don't apply it to the next branch.
2. Merge this PR and implement support for string[] on next branch.
3. Don't merge this PR, nothing to do.
4. Merge and ask for support of string[] in openid-client (opened a discussion Support scope as an array panva/node-openid-client#385)

Current implementation:

next-auth/src/server/lib/signin/oauth.js

Line 18 in be74dd0

scope: provider.scope,

next implementation:

next-auth/src/server/lib/oauth/authorization-url.js

Line 27 in b50a2eb

params = { ...params, ...provider.authorization?.params }

Note that we don't do special handling for scope here.

Update My idea to add support for this in openid-client was welcome, so I'll open a PR there, and so hopefully this will be handled in v4 as well, without us needing to change anything. So this PR is good to go!