Fix GC heap dump

[davmason]

#36932 had a typo that caused types to never be logged

Fixes#38639

[ghost]

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[davmason]

@noahfalk@sywhang If I wanted to add a test to make sure we get at least some types from the bulk type event, is the right place for it the runtime or diagnostics repo?

[sywhang]

@davmason Thanks for fixing this.. I think the right place would be the runtime repo.

[echesakov]

@davmason I noticed that test in this PR was merged under src/coreclr/tests/src while after #38058 all the tests should be under src/tests. Can you move it to right location?

[davmason]

@echesakovMSFT there's already a PR open #39057