[FF] Rollout `ci_batch_component_fetching`
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## Summary
Rollout issue for the `ci_batch_component_fetching` feature flag (`gitlab_com_derisk`).
When enabled, multiple `include:component` entries from the same project are batched into a single Gitaly `blobs_at` call instead of one call per component. This reduces Gitaly load for pipelines with many component includes.
Introduced in: !230165+
Related: #588313+
## Owners
- Slack: `#g_pipeline-authoring`
- DRI: @avielle
## Rollout Steps
### Non-production
- [ ] `/chatops gitlab run feature set ci_batch_component_fetching true --dev --pre --staging --staging-ref`
### Production
- [ ] `/chatops gitlab run feature set --project=gitlab-org/gitlab ci_batch_component_fetching true`
- [ ] `/chatops gitlab run feature set ci_batch_component_fetching 25 --actors`
- [ ] `/chatops gitlab run feature set ci_batch_component_fetching 50 --actors`
- [ ] `/chatops gitlab run feature set ci_batch_component_fetching 100 --actors`
### Cleanup
- [ ] Remove feature flag and old code path
- [ ] `/chatops gitlab run feature delete ci_batch_component_fetching --dev --pre --staging --staging-ref --production`
## Rollback
```
/chatops gitlab run feature set ci_batch_component_fetching false
```
issue