Dissector - Set config parameter target_field to init=False

[niklas-kunz]

For Dissector rules, it is not sensible to set the parameter target_field, since the name of the resulting field(s) is defined by the dissect pattern (mapping). Therefore, init should be set to False (as done e.g. in the SelectiveExtractor).

Please also review if other dissector parameters should be init=False as well.

[ekneg54]

thanks for your issue. we will address this as soon as possible by revising the config parameters for all processors and flag them with attrs option init=False if they are not needed