docs: remove experimental flag definition cache labels

[dustinbyrne]

💡 Motivation and Context

The flag definition cache provider is now supported and should no longer be documented as experimental.

Companion Ruby PR: PostHog/posthog-ruby#157
Docs PR: PostHog/posthog.com#17075

💚 How did you test it?

Verified there are no remaining experimental references with:

rg -n -i "experimental" .

No test suite run; this is a docs/comment-only change.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran sampo add to generate a changeset file

[greptile-apps]

_{Reviews (1): Last reviewed commit: "docs: remove experimental flag definitio..." | Re-trigger Greptile}

[github-actions]

posthog-python Compliance Report

Date: 2026-05-27 21:29:55 UTC
Duration: 176145ms

✅ All Tests Passed!

45/45 tests passed

---

Capture Tests

✅ 29/29 tests passed

View Details

Test	Status	Duration
Format Validation.Event Has Required Fields	✅	517ms
Format Validation.Event Has Uuid	✅	1508ms
Format Validation.Event Has Lib Properties	✅	1507ms
Format Validation.Distinct Id Is String	✅	1507ms
Format Validation.Token Is Present	✅	1508ms
Format Validation.Custom Properties Preserved	✅	1507ms
Format Validation.Event Has Timestamp	✅	1507ms
Retry Behavior.Retries On 503	✅	9517ms
Retry Behavior.Does Not Retry On 400	✅	3510ms
Retry Behavior.Does Not Retry On 401	✅	3508ms
Retry Behavior.Respects Retry After Header	✅	9515ms
Retry Behavior.Implements Backoff	✅	23528ms
Retry Behavior.Retries On 500	✅	7507ms
Retry Behavior.Retries On 502	✅	7513ms
Retry Behavior.Retries On 504	✅	7512ms
Retry Behavior.Max Retries Respected	✅	23531ms
Deduplication.Generates Unique Uuids	✅	1496ms
Deduplication.Preserves Uuid On Retry	✅	7517ms
Deduplication.Preserves Uuid And Timestamp On Retry	✅	14521ms
Deduplication.Preserves Uuid And Timestamp On Batch Retry	✅	7504ms
Deduplication.No Duplicate Events In Batch	✅	1509ms
Deduplication.Different Events Have Different Uuids	✅	1507ms
Compression.Sends Gzip When Enabled	✅	1507ms
Batch Format.Uses Proper Batch Structure	✅	1508ms
Batch Format.Flush With No Events Sends Nothing	✅	1005ms
Batch Format.Multiple Events Batched Together	✅	1506ms
Error Handling.Does Not Retry On 403	✅	3508ms
Error Handling.Does Not Retry On 413	✅	3509ms
Error Handling.Retries On 408	✅	7512ms

Feature_Flags Tests

✅ 16/16 tests passed

View Details

Test	Status	Duration
Request Payload.Request With Person Properties Device Id	✅	1007ms
Request Payload.Flags Request Uses V2 Query Param	✅	1007ms
Request Payload.Flags Request Hits Flags Path Not Decide	✅	1007ms
Request Payload.Flags Request Omits Authorization Header	✅	1007ms
Request Payload.Token In Flags Body Matches Init	✅	1007ms
Request Payload.Groups Round Trip	✅	1007ms
Request Payload.Groups Default To Empty Object	✅	1008ms
Request Payload.Person Properties Distinct Id Auto Populated When Caller Omits It	✅	1007ms
Request Payload.Disable Geoip False Propagates As Geoip Disable False	✅	1007ms
Request Payload.Disable Geoip Omitted Defaults To False	✅	1007ms
Request Payload.Flag Keys To Evaluate Contains Only Requested Key	✅	1007ms
Request Lifecycle.No Flags Request On Init Alone	✅	503ms
Request Lifecycle.No Flags Request On Normal Capture	✅	1508ms
Request Lifecycle.Two Flag Calls Produce Two Remote Requests	✅	1011ms
Request Lifecycle.Mock Response Value Is Returned To Caller	✅	1002ms
Side Effect Events.Get Feature Flag Captures Feature Flag Called Event	✅	1510ms