zitadel provider added in types.ts

[hbasria]

What kind of change does this PR introduce?

Add Zitadel Provider

What is the current behavior?

Currently, auth-js does not support Zitadel as an authentication provider.

What is the new behavior?

With this PR, Zitadel will be available as a provider for authentication, allowing users to authenticate via Zitadel's OpenID Connect (OIDC) implementation.

    const { error, data } = await supabase.auth.signInWithOAuth({
      provider: 'zitadel',
      options: {
        redirectTo: `${origin}/auth/callback`,
        scopes: 'openid'  // This parameter is important
      }
    });

Additional context

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