Fix build for typescript 4.5.4

Release-Notes: skip
Change-Id: I0d686faefc07b124963aa2c595319c9fbc4b7aed
diff --git a/polygerrit-ui/app/models/bulk-actions/bulk-actions-model.ts b/polygerrit-ui/app/models/bulk-actions/bulk-actions-model.ts
index b4fba63..07633d8 100644
--- a/polygerrit-ui/app/models/bulk-actions/bulk-actions-model.ts
+++ b/polygerrit-ui/app/models/bulk-actions/bulk-actions-model.ts
@@ -177,7 +177,7 @@
     currentState = this.subject$.getValue();
     // Return early if sync has been called again since starting the load.
     if (basicChanges !== currentState.allChanges) return;
-    const allDetailedChanges = new Map();
+    const allDetailedChanges: Map<NumericChangeId, ChangeInfo> = new Map();
     for (const detailedChange of changeDetails ?? []) {
       const basicChange = basicChanges.get(detailedChange._number)!;
       allDetailedChanges.set(