chore(AI): timestampsInChangeRequestTimeline flag cleanup (#10492)

This PR cleans up the timestampsInChangeRequestTimeline flag. These
changes were automatically generated by AI and should be reviewed
carefully.

Fixes #10491

## 🧹 AI Flag Cleanup Summary
This PR removes the `timestampsInChangeRequestTimeline` feature flag.
The
feature is now permanently enabled.
⚠️ No conditional logic for this flag was found in the provided files.
The
changes are limited to removing flag definitions and configurations. The
actual
logic may reside in other parts of the codebase not included in this
operation.
### 🚮 Removed
- **Flag Definitions & Configuration**
- Removed `timestampsInChangeRequestTimeline` from `IFlagKey` type in
`src/lib/types/experimental.ts`.
- Removed `timestampsInChangeRequestTimeline` flag configuration from
`src/lib/types/experimental.ts`.
- Removed `timestampsInChangeRequestTimeline` from the `UiFlags`
interface in
`frontend/src/interfaces/uiConfig.ts`.
- Removed the flag from the experimental flags in `src/server-dev.ts`.
### 🛠 Kept
- **Feature Functionality**
- The behavior previously enabled by the
`timestampsInChangeRequestTimeline`
flag is now the default and only behavior.
### 📝 Why
The `timestampsInChangeRequestTimeline` feature flag was marked as
completed
with an intended outcome of "kept". This means the feature has been
rolled out
successfully and should be permanent. This cleanup removes the obsolete
flag and
its related configurations, simplifying the code and adhering to best
practices
for feature flag lifecycle management.

Co-authored-by: unleash-bot <194219037+unleash-bot[bot]@users.noreply.github.com>

frontend/src/interfaces/uiConfig.ts

@@ -92,7 +92,6 @@ export type UiFlags = {
     impactMetrics?: boolean;
     crDiffView?: boolean;
     changeRequestApproverEmails?: boolean;
-    timestampsInChangeRequestTimeline?: boolean;
     reportUnknownFlags?: boolean;
     lifecycleGraphs?: boolean;
     addConfiguration?: boolean;

src/lib/types/experimental.ts

@@ -63,7 +63,6 @@ export type IFlagKey =
     | 'changeRequestApproverEmails'
     | 'paygTrialEvents'
     | 'paygInstanceStatsEvents'
-    | 'timestampsInChangeRequestTimeline'
     | 'lifecycleGraphs'
     | 'addConfiguration'
     | 'filterFlagsToArchive'
@@ -295,10 +294,6 @@ const flags: IFlags = {
         process.env.UNLEASH_EXPERIMENTAL_PAYG_INSTANCE_STATS_EVENTS,
         false,
     ),
-    timestampsInChangeRequestTimeline: parseEnvVarBoolean(
-        process.env.UNLEASH_EXPERIMENTAL_TIMESTAMPS_IN_CHANGE_REQUEST_TIMELINE,
-        false,
-    ),
     lifecycleGraphs: parseEnvVarBoolean(
         process.env.UNLEASH_EXPERIMENTAL_LIFECYCLE_GRAPHS,
         false,

src/server-dev.ts

@@ -58,7 +58,6 @@ process.nextTick(async () => {
                         impactMetrics: true,
                         crDiffView: true,
                         paygTrialEvents: true,
-                        timestampsInChangeRequestTimeline: true,
                         lifecycleGraphs: true,
                         addConfiguration: true,
                         projectListViewToggle: true,