Issues uncovered by SHACL validation

[acka47]

Collecting some problems that are reported with the SHACL validation in #4 (see https://github.com/hbz/skos-ressources4ktbl/actions/runs/11126292292/job/30915882555?pr=4):

• <livestock_production/chicken_fattening> is mentioned in

  skos-ressources4ktbl/emimin.ttl

  Line 267 in c93abd4

  skos:broader <livestock_production/chicken_fattening> ;

  but is not further described in the vocab
• livestock_production/piglet_procuction> is mentioned in

  skos-ressources4ktbl/emimin.ttl

  Line 736 in c93abd4

  skos:broader <livestock_production/piglet_procuction> ;

  but not further described in the vocab. (Probably a typo)
• "Manure belt" exists twice:

  skos-ressources4ktbl/emimin.ttl

  Lines 589 to 592 in c93abd4

  	<emission_reduction_methods/manure_belt> a skos:Concept ;
  	skos:prefLabel "Manure belt (MB)"@en, "Kotband"@de ;
  	skos:broader <emission_reduction_methods> ;
  	skos:inScheme <> .

  &

  skos-ressources4ktbl/emimin.ttl

  Lines 439 to 444 in c93abd4

  	<additional_housing_systems/manure_belt> a skos:Concept ;
  	skos:prefLabel "Manure belt"@en, "Kotband"@de ;
  	skos:broader <additional_housing_systems> ;
  	skos:broader <laying_hen> ;
  	skos:broader <young_hen> ;
  	skos:inScheme <> .

  Why not have one concept for this with two place in the hierarchy?