fix: update Custom Token Exchange limitations

[dlozlla]

Description

Updates the Custom Token Exchange (CTE) limitations section on the overview page (main/docs/authenticate/custom-token-exchange.mdx):

• Removed the Organization + MFA limitation (api.multifactor.enable() and MFA policies not supported when associated with an Organization), which is no longer accurate.
• Added a missing limitation about consent: the target API must have Allow Skipping User Consent enabled, since consent cannot be collected in a non-interactive flow. This was already documented in the French-Canadian and Japanese translations but missing from the English source page.

References

• Server-side enforcement: CustomTokenExchangeProfile.js — #consentRequired() method rejects requests when the resource server does not allow skipping consent for first-party clients.

Testing

• Run mint dev from the main/ directory and navigate to the /docs/authenticate/custom-token-exchange to verify the updated limitations list renders correctly.

Checklist

• I've read and followed CONTRIBUTING.md.
• I've tested the site build for this change locally.
• I've made appropriate docs updates for any code or config changes.
• I've coordinated with the Product Docs and/or Docs Management team about non-trivial changes.

[avanscoy]

You don't need the comma here.