checker: disallow printing void (#17901)

vlib/v/checker/fn.v

@@ -2436,6 +2436,7 @@ fn (mut c Checker) array_builtin_method_call(mut node ast.CallExpr, left_type as
 		if method := c.table.find_method(unwrapped_left_sym, method_name) {
 			node.receiver_type = method.receiver_type
 		}
+		node.return_type = ast.void_type
 	}
 	return node.return_type
 }

vlib/v/checker/tests/array_delete_print_err.out

@@ -0,0 +1,13 @@
+vlib/v/checker/tests/array_delete_print_err.vv:3:2: error: `println` can not print void expressions
+    1 | fn main() {
+    2 |     a := []string{}
+    3 |     println(a.delete(0))
+      |     ~~~~~~~~~~~~~~~~~~~~
+    4 |     println('${a.delete(0)}')
+    5 | }
+vlib/v/checker/tests/array_delete_print_err.vv:4:15: error: expression does not return a value
+    2 |     a := []string{}
+    3 |     println(a.delete(0))
+    4 |     println('${a.delete(0)}')
+      |                  ~~~~~~~~~
+    5 | }

vlib/v/checker/tests/array_delete_print_err.vv

@@ -0,0 +1,5 @@
+fn main() {
+	a := []string{}
+	println(a.delete(0))
+	println('${a.delete(0)}')
+}