minor #8001 Update database.rst (Max93)

This PR was merged into the 3.3 branch.

Discussion
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Update database.rst

Fix typo: EntityManagerInterface to EntityRepository

Commits
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a3271a2 Update database.rst

Author: xabbuh

testing/database.rst

@@ -87,7 +87,7 @@ it's easy to pass a mock object within a test::
 
             // Now, mock the repository so it returns the mock of the employee
             $employeeRepository = $this
-                ->getMockBuilder(EntityManagerInterface::class)
+                ->getMockBuilder(EntityRepository::class)
                 ->disableOriginalConstructor()
                 ->getMock();
             $employeeRepository->expects($this->once())