chore: update payment guide in payment unsupported msg

[foochifa]

Problem

Payment guide has been updated, we can publish it now

Closes #6014

Solution

Update PaymentsUnsupportedMsg

Breaking Changes

• No - this PR is backwards compatible

Before & After Screenshots

AFTER:

Tests

• go to an email mode form. Go to settings, make sure that the settings page is as seen in the screenshot
• go to the payment guide link, make sure that it can open

[LinHuiqing]

Just to double check, are these the right links for the guide? it goes https://go.gov.sg/formsg-guide-payments -> https://app.tango.us/app/workflow/Creating-payment-forms-2eb9521debdf41fe8152f78052286059

Was a bit thrown off by the Tango logo haha

[LinHuiqing]

LGTM and tested! Approving since the link is to the go.gov.sg link, and my comments are on the guide link and the guide itself.

[LinHuiqing]

@kennethchangOPENGOV some other comments on the guide itself:

1. We can consider shifting the opening of the form down or excluding these steps since we want to block payment-related changes from being made when the form is open in the future, right?

2. There's an untitled step here:

[LinHuiqing]

Merge when we're sure we're ready to publish the guide considering the above comments bah^

[kennethchangOPENGOV]

made amendments