Remove dangling static to avoid memory leaks on the heap.

[gaurarpit]

This pull request includes changes to the PdsServiceTests.cs file in the tests/Integration.Tests/Core/Pds directory. The main changes involve modifying two methods, CreateDummyMeshPatientMessage and CreatePatient, from being static methods to instance methods.

Here are the key changes:

• tests/Integration.Tests/Core/Pds/PdsServiceTests.cs: The CreateDummyMeshPatientMessage method was changed from a static method to an instance method.
• tests/Integration.Tests/Core/Pds/PdsServiceTests.cs: Similarly, the CreatePatient method was also changed from a static method to an instance method..