Stop requesting JCB capability for JP merchants

[anu-rock]

Description

Stripe will automatically enable JCB payments for new and existing accounts starting April 22. However, JCB will continue to review all accounts and may reject some.

Note that this capability was previously auto-enabled for eligible non-JP merchants.

Acceptance criteria

• Remove the capability request notice shown to JP merchants.
• Remove any other code that helps in requesting/enabling the jcb_payments capability.
• Preserve the notice when the JCB capability request is rejected.
• Ensure that Kana statement descriptors, company names, and representative names will only accept kana, dots, spaces, and hyphens.

Dev notes

Basically, undo relevant changes in these PRs:

• Add JCB as a coming soon to the list of available payment methods #6905 (???)
• Add JCB capability request notice #7224

Based on what I see here, we are requesting jcb_payments capability only for JP merchants (not automatically, but on demand). Sounds like we should remove that treatment.

Additional context

• pbUcTB-6a6-p2
• p1738791307556349-slack-C9976E5MJ