Remove any references of va_online_scheduling_descriptive_back_link feature toggle

[ldelacosta]

Description

We no longer need to reference the feature toggle va_online_scheduling_descriptive_back_link in the frontend code. The Descriptive Back Link work was deployed on August 2, 2023. The product team is requesting to remove any references of the feature toggle.

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Acceptance Criteria

• [x] Remove any references of the feature toggle va_online_scheduling_descriptive_back_link
• [x] Delete the feature toggle va_online_scheduling_descriptive_back_link in staging and production
• [x] Changes have been updated in vets-website and vets-api

Design Assets

N/A

Definition of Done

• [ ] All acceptance criteria are met
• [x] Documentation is updated

[ldelacosta]

Low priority ticket for frontend. We will work on this post MHV on VA.gov work.

[ldelacosta]

@young1205 - please notify @JRRoof to validate

[JRRoof]

No longer shows in VA.gov Flipper Admin in Staging. Still appears in Production.

@jenniemc - Does this change still need to be put in Production?

[jenniemc]

@JRRoof ,Platform support assured me the toggle was removed from both staging and production. https://dsva.slack.com/archives/CBU0KDSB1/p1700071404412209 I'll reach out to them again.

[jenniemc]

@JRRoof , Platform support removed the toggle this morning from production. Please validate.

[ldelacosta]

Validated the feature toggleva_online_scheduling_descriptive_back_linkis no longer available in staging and production. Closing out the ticket.