fix: Delete contributorsCount in the code

Author: ChrisChV

src/library-authoring/data/api.mocks.ts

@@ -1311,7 +1311,6 @@ mockLibraryBlockPublishHistory.data = [
     publishedBy: 'author',
     publishedAt: '2026-03-14T10:00:00Z',
     contributors: ['test_user_1', 'test_user_2', 'test_user_3', 'test_user_4', 'test_user_5'].map(mockContributor),
-    contributorsCount: 5,
   },
 ] as api.LibraryPublishHistoryGroup[];
 mockLibraryBlockPublishHistory.applyMock = () =>
@@ -1457,7 +1456,6 @@ mockLibraryContainerPublishHistory.data = [
     publishedBy: 'container_author',
     publishedAt: '2026-03-14T10:00:00Z',
     contributors: ['container_user_1', 'container_user_2'].map(mockContributor),
-    contributorsCount: 2,
   },
 ] satisfies api.LibraryPublishHistoryGroup[];
 mockLibraryContainerPublishHistory.applyMock = () =>

src/library-authoring/data/api.ts

@@ -988,7 +988,6 @@ export interface LibraryPublishHistoryGroup {
   publishedBy?: string;
   publishedAt: string;
   contributors: LibraryPublishContributor[];
-  contributorsCount: number;
   /**
    * Key to use as `scope_entity_key` when fetching entries for this group.
    * Pre-Verawood: the specific entity key for this group (container or usage key).

src/library-authoring/generic/history-log/HistoryLog.test.tsx

@@ -169,7 +169,6 @@ describe('<HistoryComponentLog />', () => {
       {
         ...originalData[0],
         contributors: [],
-        contributorsCount: 0,
       },
     ];
     renderComponent(mockLibraryBlockCreationEntry.usageKey);