1. Fixes: https://github.com/go-gitea/gitea/issues/39641
* The OAuth2 authorize/grant endpoint accepted and persisted arbitrary
scope strings without validation, unlike personal access token creation
which rejects unknown scopes. Normalize and validate form.Scope before
creating or updating a grant, ignore invalid scopes
* `// TODO: at the moment invalid tokens are treated as "all" to avoid
breaking 1.22 behavior` is fixed.
2. To avoid CSRF attack for OpenID endpoint, add a state check
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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>