Failure to import key with attached packet of uknown packet number 60 even in permissive mode.

[ni4]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1997493, sample key is available privately (basically, just packet #60 with some contents after the primary key and subkey).

Sample code to reproduce:

    assert_rnp_success(rnp_ffi_create(&ffi, "GPG", "GPG"));
    assert_rnp_success(rnp_input_from_path(&input, "data/test_stream_key_load/bug1997493_public.asc"));
    assert_rnp_success(rnp_import_keys(ffi, input, RNP_LOAD_SAVE_PUBLIC_KEYS | RNP_LOAD_SAVE_PERMISSIVE, NULL));