Add extra check for cms signature before parsing

[NicoHinderling]

Should address this error we were seeing

Failed to parse CMS signature
Traceback (most recent call last):
  File "/app/src/launchpad/parsers/apple/code_signature_parser.py", line 591, in _parse_signature
    signature = cms.ContentInfo.load(signature_content)  # type: ignore[attr-defined]
  File "/usr/local/lib/python3.13/site-packages/asn1crypto/core.py", line 230, in load
    value, _ = _parse_build(encoded_data, spec=spec, spec_params=kwargs, strict=strict)
               ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/asn1crypto/core.py", line 5672, in _parse_build
    info, new_pointer = _parse(encoded_data, encoded_len, pointer)
                        ~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/asn1crypto/parser.py", line 173, in _parse
    raise ValueError(_INSUFFICIENT_DATA_MESSAGE % (1, data_len - pointer))
ValueError: Insufficient data - 1 bytes requested but only 0 available