ref(develop): Remove "option backed features" docs (#14295)

These should no longer be used and are currently being removed

Part of [CORE-24: Remove "option backed" feature
flags](https://linear.app/getsentry/issue/CORE-24/remove-option-backed-feature-flags)

Author: evanpurkhiser

develop-docs/backend/application-domains/feature-flags/index.mdx

@@ -21,9 +21,6 @@ manager.add("organizations:onboarding", OrganizationFeature, FeatureHandlerStrat
 
 # pass FeatureHandlerStrategy.INTERNAL if you don't plan to use options automator:
 manager.add("organizations:onboarding", OrganizationFeature, FeatureHandlerStrategy.INTERNAL)
-
-# [DEPRECATED] pass FeatureHandlerStrategy.OPTIONS to use options automator:
-manager.add("organizations:onboarding", OrganizationFeature, FeatureHandlerStrategy.OPTIONS)
 ```
 
 The feature can be enabled with the following in your `sentry.conf.py`, usually located at `~/.sentry/`:
@@ -194,14 +191,9 @@ flags are then configured via `sentry.conf.py`. For Sentry's SaaS deployment,
 you have the choice of using an option backed rollout via Options Automator with Flagpole,
 or by writing a custom feature flag handler.
 
-- [Flagpole](/backend/feature-flags/flagpole/) is Sentry's internal feature flagging library, allowing a feature
-  with multiple target segments and condition filters to be defined in YAML within Options Automator.
-
-- [Options based features](options-backed-features/) [DEPRECATED] allow a feature
-  to be rolled out to a specific subset of LA orgs, a percentage of EA orgs,
-  and/or a percentage of all orgs. These can be used in high scale situations, and are generally
-  preferred over customer feature handlers. This strategy predates Flagpole, which is the new standard
-  way to define an option-backed feature flag.
+[Flagpole](/backend/feature-flags/flagpole/) is Sentry's internal feature
+flagging library, allowing a feature with multiple target segments and
+condition filters to be defined in YAML within Options Automator.
 
 ## After launch (Graduation)
 

develop-docs/backend/application-domains/feature-flags/options-backed-features.mdx

@@ -3574,10 +3574,6 @@ const DEVELOPER_DOCS_REDIRECTS: Redirect[] = [
     from: '/feedback-architecture/',
     to: '/application/feedback-architecture/',
   },
-  {
-    from: '/feature-flags/options-backed-features/',
-    to: '/application/feature-flags/options-backed-features/',
-  },
   {
     from: '/options/',
     to: '/backend/options/',
@@ -3788,14 +3784,6 @@ const DEVELOPER_DOCS_REDIRECTS: Redirect[] = [
     from: '/api-server/application-domains/feature-flags/flagpole/',
     to: '/develop/application-domains/feature-flags/flagpole/',
   },
-  {
-    from: '/backend/feature-flags/options-backed-features/',
-    to: '/backend/application-domains/feature-flags/options-backed-features/',
-  },
-  {
-    from: '/api-server/application-domains/feature-flags/options-backed-features/',
-    to: '/develop/application-domains/feature-flags/options-backed-features/',
-  },
   {
     from: '/backend/options/',
     to: '/backend/application-domains/options/',