Fix kaitai py tests (#1410)

# Description

@swift-nav/devinfra

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# API compatibility

Does this change introduce a API compatibility risk?

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## API compatibility plan

If the above is "Yes", please detail the compatibility (or migration)
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# JIRA Reference

https://swift-nav.atlassian.net/browse/BOARD-XXXX

Author: woodfell

kaitai/python/kaitai_sbp/tests/utils.py

@@ -7,7 +7,7 @@
 import sys
 import sbp.msg as msg_construct
 import sbp.table as table_construct
-from sbp.sbp2json import iter_messages as parse_file_construct
+from sbp.sbp2json import iter_messages_buffered as parse_file_construct
 from subprocess import Popen, PIPE
 
 SBP_HEADER_LEN = 6