[lldb] Change TestPublicAPIHeaders.py to only build when the target architecture matches the host's (#193848)
This test requires that LLDB.framework be built the same architecture as
the test binary (effectively). There's no way to specify that in our
testing logic currently, so let's just mark this test as arm64 only for
now.
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Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>