Fix inputRelationship count returned in ToUndirected

Author: FlorentinD

doc/modules/ROOT/pages/graph-catalog-relationship-ops.adoc

@@ -685,7 +685,7 @@ YIELD
 [opts="header"]
 |===
 | inputRelationships      | relationshipsWritten
-| 19                       | 18
+| 9                       | 18
 |===
 --
 

proc/beta/src/main/java/org/neo4j/gds/beta/undirected/ToUndirectedSpec.java

@@ -65,7 +65,9 @@ protected AbstractResultBuilder<MutateResult> resultBuilder(
         ComputationResult<ToUndirected, SingleTypeRelationships, ToUndirectedConfig> computeResult,
         ExecutionContext executionContext
     ) {
-        return new MutateResult.Builder().withInputRelationships(computeResult.graph().relationshipCount());
+        return new MutateResult.Builder().withInputRelationships(computeResult
+            .graphStore()
+            .relationshipCount(RelationshipType.of(computeResult.config().relationshipType())));
     }
 
     @Override