Complete edx-sphinx-theme DEPR in edx org

[robrap]

AC:

• [ ] Usage of edx-sphinx-theme in the edx org has been removed.

Additional Notes:

• DEPR: https://github.com/openedx-unsupported/edx-sphinx-theme/issues/184
• Instructions: https://docs.openedx.org/en/latest/developers/how-tos/switch-to-the-sphinx-book-theme.html
• The repos in the edx GitHub org that still depend on this theme:

### Tasks
- [ ] [braze-client](https://github.com/edx/braze-client/pull/29)
- [ ] [commerce-coordinator](https://github.com/edx/commerce-coordinator/pull/259)
- [ ] [dbt-schema-builder](https://github.com/edx/dbt-schema-builder/pull/98)
- [ ] [demographics](https://github.com/edx/demographics/pull/380)
- [ ] [edx-arch-experiments](https://github.com/edx/edx-arch-experiments/pull/763)
- [ ] [edx-exams](https://github.com/edx/edx-exams/issues/299)
- [ ] [edx-name-affirmation](https://github.com/edx/edx-name-affirmation/issues/208)
- [ ] [financial-assistance](https://github.com/edx/financial-assistance/issues/54)
- [ ] [getsmarter-api-clients](https://github.com/edx/getsmarter-api-clients/issues/23)
- [ ] [learner-pathway-progress](https://github.com/edx/learner-pathway-progress/pull/25)
- [ ] [monitoring-scripts](https://github.com/edx/monitoring-scripts/pull/128)
- [ ] [outcome-surveys](https://github.com/edx/outcome-surveys/pull/20)
- [ ] platform-plugin-coaching (unable to write to this and forking is also disabled)
- [ ] [platform-plugin-notices](https://github.com/edx/platform-plugin-notices/pull/220)
- [ ] [portal-designer](https://github.com/edx/portal-designer/issues/337)
- [ ] [program-intent-engagement](https://github.com/edx/program-intent-engagement/pull/138)
- [ ] [subscriptions](https://github.com/edx/subscriptions/pull/209)
- [ ] [video-encode-manager](https://github.com/edx/video-encode-manager/pull/460)

• The common constraint was removed, but we think that upgrades may be picking up the right version for some reason, which is good. Otherwise, this constraint would need to be copied into the other repos. See https://github.com/openedx-unsupported/edx-sphinx-theme/issues/184
  • I closed the ticket to remove this common constraint: https://github.com/openedx/edx-lint/issues/338

[huniafatima-arbi]

We are waiting on the information to be added in license and author section which is to be updated as the edx-sphinx-theme is being replaced by sphinx-book-theme. Slack thread for more information. Moving it to blocked until the issue is resolved.