Merge branch 'ballot/5' into develop

Lands Ballot 5: refresh outdated ontology/shapes metadata and switch to
owl:versionIRI (dct:modified 2026-06-01; versionIRI .../2026-06-01/ and
.../2026-06-01/shapes/), replacing the stale owl:versionInfo "Errata 2".

Resolves: DPROD-64, #192

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: jgeluk

ontology/dprod/dprod-ontology.ttl

@@ -27,7 +27,7 @@ dprod:
     "The ontology utilizes the notion of Datasets as defined from DCAT vocabulary."@en ;
   rdfs:comment "DPROD is an OWL ontology designed to facilitate interoperability between data product descriptors."@en ;
   dct:license <https://creativecommons.org/licenses/by/4.0/> ;
-  dct:modified "2024-08-31"^^xsd:date ;
+  dct:modified "2026-06-01"^^xsd:date ;
   dct:publisher <https://www.omg.org/> ;
   dct:contributor <https://www.linkedin.com/in/matthiasautrata> ;
   dct:contributor <https://www.linkedin.com/in/natasavaritimou> ;
@@ -38,7 +38,7 @@ dprod:
   dct:contributor <https://www.linkedin.com/in/tonyseale> ;
   dct:contributor <https://www.linkedin.com/in/joshuacornejo> ;
   owl:imports dcat: ;
-  owl:versionInfo "OMG Request For Comments Errata 2" ;
+  owl:versionIRI <https://www.omg.org/spec/DPROD/2026-06-01/> ;
 .
 
 ############################# DPROD Classes  #########################

ontology/dprod/dprod-shapes.ttl

@@ -26,7 +26,7 @@ dprod-shapes:
   dct:description "SHACL shapes for DPROD, including the DCAT classes and properties to be used."@en ;
   rdfs:comment
     "This is intended to be used with SHACL, not as an ontology: the ontology element is to provide the metadata for the set of shapes."@en ;
-  dct:modified "2024-08-31"^^xsd:date ;
+  dct:modified "2026-06-01"^^xsd:date ;
   dct:contributor <https://www.linkedin.com/in/natasavaritimou> ;
   dct:contributor <https://www.linkedin.com/in/peterivett> ;
   dct:contributor <https://www.linkedin.com/in/jgeluk> ;
@@ -36,7 +36,7 @@ dprod-shapes:
   owl:imports dcat: ;
   owl:imports sh: ;
   owl:imports dprod: ;
-  owl:versionInfo "OMG Request For Comments Errata 2" ;
+  owl:versionIRI <https://www.omg.org/spec/DPROD/2026-06-01/shapes/> ;
   sh:declare [
     sh:prefix "dprod" ;
     sh:namespace "https://www.omg.org/spec/DPROD/" ;