Remove typeorm service (#14116)

## Context
To simplify the way we inject our default datasource, I've recently
removed the token injection that was confusion since we only had once
configured on the module level. Now I'm removing TypeORM service which
allows us to instantiate a new Datasource with the same parameters as
the default one, it was redundant and confusing.

packages/twenty-server/src/engine/workspace-manager/dev-seeder/metadata/services/dev-seeder-metadata.service.ts

@@ -1,8 +1,8 @@
 import { Injectable } from '@nestjs/common';
+import { InjectDataSource } from '@nestjs/typeorm';
 
-import { isDefined } from 'class-validator';
+import { DataSource } from 'typeorm';
 
-import { TypeORMService } from 'src/database/typeorm/typeorm.service';
 import { type DataSourceEntity } from 'src/engine/metadata-modules/data-source/data-source.entity';
 import { FieldMetadataService } from 'src/engine/metadata-modules/field-metadata/services/field-metadata.service';
 import { ObjectMetadataService } from 'src/engine/metadata-modules/object-metadata/object-metadata.service';
@@ -26,7 +26,8 @@ export class DevSeederMetadataService {
   constructor(
     private readonly objectMetadataService: ObjectMetadataService,
     private readonly fieldMetadataService: FieldMetadataService,
-    private readonly typeORMService: TypeORMService,
+    @InjectDataSource()
+    private readonly coreDataSource: DataSource,
   ) {}
 
   private readonly workspaceConfigs: Record<
@@ -152,15 +153,13 @@ export class DevSeederMetadataService {
   }
 
   private async seedCoreViews(workspaceId: string): Promise<void> {
-    const mainDataSource = this.typeORMService.getMainDataSource();
-
-    if (!isDefined(mainDataSource)) {
-      throw new Error('Could not connect to main data source');
-    }
-
     const createdObjectMetadata =
       await this.objectMetadataService.findManyWithinWorkspace(workspaceId);
 
-    await prefillCoreViews(mainDataSource, workspaceId, createdObjectMetadata);
+    await prefillCoreViews(
+      this.coreDataSource,
+      workspaceId,
+      createdObjectMetadata,
+    );
   }
 }