lldb-dap does not step into target given by targetId

[kendalharland]

See #96687 for additional context.

When DapTestCaseBase.stepIn is called the dap steps into the first target from step_in_targets regardless of the given targetId.

[kendalharland]

I'll need someone with write-access to add the lldb-dap labels to this issue.

Edit. Thanks @EugeneZelenko!

[kendalharland]

Fixed w/ same explanation as #100284