feat(perf-vitals): Add INP feature flag (#39029)

### Summary
We may want to add interaction transactions for INP so we should be
putting INP behind a feature flag in case this requires more UI
features.

Author: k-fish

src/sentry/conf/server.py

@@ -1126,6 +1126,8 @@ def create_partitioned_queues(name):
     "organizations:performance-span-tree-autoscroll": False,
     # Enable transaction name only search
     "organizations:performance-transaction-name-only-search": False,
+    # Enable showing INP web vital in default views
+    "organizations:performance-vitals-inp": False,
     # Enable the new Related Events feature
     "organizations:related-events": False,
     # Enable populating suggested assignees with release committers

src/sentry/features/__init__.py

@@ -123,6 +123,7 @@
 default_manager.add("organizations:performance-suspect-spans-view", OrganizationFeature, True)
 default_manager.add("organizations:performance-transaction-name-only-search", OrganizationFeature, True)
 default_manager.add("organizations:performance-use-metrics", OrganizationFeature, True)
+default_manager.add("organizations:performance-vitals-inp", OrganizationFeature, True)
 default_manager.add("organizations:profiling", OrganizationFeature)
 default_manager.add("organizations:project-event-date-limit", OrganizationFeature, True)
 default_manager.add("organizations:related-events", OrganizationFeature)