fix(corekit): before Python 3.10 an Info subclass with no annotations of its own inherits Info's, so its generated __init__ takes the wrong arguments #1692

Describe the bug
pcapkit/corekit/infoclass.py:170 reads cls_.__annotations__ for each class in the MRO.

Before Python 3.10 (bpo-43901), a class body with no annotations has no __annotations__ of its own, so the lookup returns the nearest base's. For a direct Info subclass that is Info's own __finalised__, __additional__ and __excluded__.

The generated constructor therefore differs by version:

Building such a subclass from a mapping raises TypeError on 3.6–3.9.

Reproduction
Three tests fail on both legs:

• tests/corekit/test_infoclass.py::InfoClassTests::test_auto_finalised_info_mapping_update_and_builtin_key_remapping: __init__() got an unexpected keyword argument 'extra'.
• Two in tests/utilities/test_stacklevel.py::StacklevelAttributionTests, through Probe(Info) at :83: __init__() missing 3 required positional arguments: '__finalised__', '__additional__', and '__excluded__'.
  • test_error_log_blames_the_same_line_from_every_depth
  • test_error_log_is_attributed_to_neither_pcapkit_nor_logging

I measured both signatures on 3.9 and 3.10.

Expected behavior
Read only a class's own annotations, cls_.__dict__.get('__annotations__', {}). The same pre-3.10 pitfall may affect four writes to cls.__annotations__[...], which would write into a base's dict: pcapkit/protocols/internet/ipv4.py:74, :150, :345 and pcapkit/protocols/internet/ipv6.py:76. I have not checked those.

Found while triaging main's KTLO legs at f20d0a600: Python 3.8 (KTLO) job 115570853800 (27 failed) and Python 3.9 (KTLO) job 115570853966 (9 failed). Since #1672, KTLO legs exit 0, so this shows only as a ::warning. Reproduced locally on CPython 3.8.20 and 3.9.25.