chore: Use default repo methods when possible (#32997)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Introduced new functionalities to count and retrieve Git-connected
applications within a specific workspace.
  
- **Bug Fixes**
- Removed outdated method for counting applications by workspace ID to
enhance performance and accuracy.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

app/server/appsmith-server/src/main/java/com/appsmith/server/repositories/ce/ApplicationRepositoryCE.java

@@ -17,6 +17,8 @@ public interface ApplicationRepositoryCE extends BaseRepository<Application, Str
 
     Flux<Application> findByWorkspaceId(String workspaceId);
 
+    Mono<Long> countByWorkspaceId(String workspaceId);
+
     Flux<IdOnly> findIdsByWorkspaceId(String workspaceId);
 
     Flux<Application> findByClonedFromApplicationId(String clonedFromApplicationId);

app/server/appsmith-server/src/main/java/com/appsmith/server/repositories/ce/CustomApplicationRepositoryCE.java

@@ -56,8 +56,6 @@ Mono<Application> getApplicationByGitBranchAndDefaultApplicationId(
     Mono<Integer> setAppTheme(
             String applicationId, String editModeThemeId, String publishedModeThemeId, AclPermission aclPermission);
 
-    Mono<Long> countByWorkspaceId(String workspaceId);
-
     Mono<Long> getGitConnectedApplicationWithPrivateRepoCount(String workspaceId);
 
     Flux<Application> getGitConnectedApplicationByWorkspaceId(String workspaceId);

app/server/appsmith-server/src/main/java/com/appsmith/server/repositories/ce/CustomApplicationRepositoryCEImpl.java

@@ -163,13 +163,6 @@ public Flux<Application> getApplicationByGitDefaultApplicationId(
                 .all();
     }
 
-    @Override
-    public Mono<Long> countByWorkspaceId(String workspaceId) {
-        return queryBuilder()
-                .criteria(Bridge.equal(Application.Fields.workspaceId, workspaceId))
-                .count();
-    }
-
     @Override
     public Mono<Long> getGitConnectedApplicationWithPrivateRepoCount(String workspaceId) {
         return queryBuilder()