title: Error message TypeError: this.subQuery is not a function appears
body: <p>If I run the tests with jest, I got always the error message <code>TypeError: this.subQuery is not a function</code> with a reference on the marked line in the testModelDb.test.ts file</p>
  <p>tests/jest.setup.ts</p>
  <pre><code>import 'reflect-metadata';
  import dotenv from 'dotenv';
  dotenv.config({ path: './.env.test' });
  </code></pre>
  <p>.env.test</p>
  <pre><code>TYPEORM_CONNECTION=sqlite
  TYPEORM_DATABASE=:memory:
  TYPEORM_SYNCHRONIZE=true
  TYPEORM_LOGGING=false
  TYPEORM_ENTITIES=dist/models/**/*.js,modules/**/entity/*.ts
  TYPEORM_MIGRATIONS=dist/services/db/seeding.js
  TYPEORM_MIGRATIONS_RUN=true
  </code></pre>
  <p>src/models/test.model.ts</p>
  <pre><code>@Entity()
  export default class TestModel {
      @PrimaryGeneratedColumn()
      id!: number;
  
      @Column()
      name!: string;
  
      @OneToMany(() =&gt; OtherModel, (other) =&gt; other.testModel)
      otherModels!: OtherModel[];
  }
  </code></pre>
  <p>tests/testModelDb.test.ts</p>
  <pre><code>describe('Integrationtests', () =&gt; {
      let connection: Connection;
  
      beforeAll(async () =&gt; { connection = await createConnection(); });
  
      afterAll(() =&gt; connection?.close());
  
      beforeEach(async () =&gt; { await connection.synchronize(true); });
  
      describe(`functions`, () =&gt; {
          describe(`#function1()`, () =&gt; {
              test('Test 1', async () =&gt; {
                  await connection
                      .createQueryBuilder()
                      .insert()
                      .into(TestModel) // &lt;- here
                      .values([ {name: 'Test item 1'} ])
                      .execute();
                
                  expect(true).toBe(true);
                  
              });
          });
      });
  });
  </code></pre>