Suppress invalid R# warning about invalid metadata in MSBuild targets file

Author: bkoelman

JsonApiDotNetCore.sln.DotSettings

@@ -84,6 +84,7 @@
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=SuggestDiscardDeclarationVarStyle/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=TailRecursiveCall/@EntryIndexedValue">SUGGESTION</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=TryCastAlwaysSucceeds/@EntryIndexedValue">WARNING</s:String>
+	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnknownMetadata/@EntryIndexedValue">DO_NOT_SHOW</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UnnecessaryWhitespace/@EntryIndexedValue">HINT</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseArrayEmptyMethod/@EntryIndexedValue">WARNING</s:String>
 	<s:String x:Key="/Default/CodeInspection/Highlighting/InspectionSeverities/=UseCollectionCountProperty/@EntryIndexedValue">WARNING</s:String>