Fix test assertions in TestDAP_stepInTargets.py (#96687)
The strings this test is using seem to consistently fail to match
against the expected values when built & run targeting Windows amd64.
This PR updates them to the expected values.
To fix the test and avoid over-specifying for a specific platform, use
`assertIn(<target-substring>,...)` to see if we've got the correct
target label instead of comparing the demangler output for an exact
string match.
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Co-authored-by: kendal <kendal@thebrowser.company>
