TSL: Fix primitive vector conversion, `vec*` with `ivec*` (#31793)

src/nodes/utils/JoinNode.js

@@ -95,7 +95,9 @@ class JoinNode extends TempNode {
 
 			if ( inputPrimitiveType !== primitiveType ) {
 
-				inputSnippet = builder.format( inputSnippet, inputPrimitiveType, primitiveType );
+				const targetType = builder.getTypeFromLength( inputTypeLength, primitiveType );
+
+				inputSnippet = builder.format( inputSnippet, inputType, targetType );
 
 			}