Revert "fix: do not fail validation for target nodes that don't exist"

This reverts commit 48ad810.

# Conflicts:
#	src/shapes-graph.js
#	test/data/data-shapes/custom/manifest.ttl
#	test/data/data-shapes/custom/targetNodeDoesNotExist.ttl

Author: tpluscode

src/shapes-graph.ts

@@ -336,14 +336,7 @@ export class Shape {
       results.addAll(getInstancesOf(dataGraph.node(targetClass), ns))
     })
 
-    const targetNodes = this.shapeNodePointer.out(sh.targetNode).terms
-      // Ensure the node exists in data graph before considering it as a validatable target node
-      .filter((targetNode) => (
-        dataGraph.dataset.match(targetNode).size > 0 ||
-        dataGraph.dataset.match(null, targetNode).size > 0 ||
-        dataGraph.dataset.match(null, null, targetNode).size > 0
-      ))
-    results.addAll(targetNodes)
+    results.addAll(this.shapeNodePointer.out(sh.targetNode).terms)
 
     this.shapeNodePointer
       .out(sh.targetSubjectsOf)

test/data/data-shapes/custom/manifest.ttl

@@ -9,7 +9,6 @@
 	mf:include <uniqueLang-false.ttl> ;
 	mf:include <multiLevelInheritance.ttl> ;
 	mf:include <multiLevelInheritanceWithImplicitTarget.ttl> ;
-	mf:include <targetNodeDoesNotExist.ttl> ;
 	mf:include <lessThan-moreTypes.ttl> ;
 	mf:include <circularReferences.ttl> ;
 	mf:include <and-minCount.ttl> ;