parser: fix block position's last line (vlang#22913)

vlib/v/fmt/fmt.v

@@ -443,13 +443,6 @@ fn (f &Fmt) should_insert_newline_before_node(node ast.Node, prev_node ast.Node)
 			ast.Import {
 				return false
 			}
-			ast.Block {
-				if node is ast.Block && !node.is_unsafe && node.pos.line_nr - prev_line_nr > 0 {
-					return true
-				} else {
-					return false
-				}
-			}
 			ast.ConstDecl {
 				if node !is ast.ConstDecl && !(node is ast.ExprStmt && node.expr is ast.Comment) {
 					return true

vlib/v/fmt/tests/block_with_blank_line_keep.vv

@@ -0,0 +1,8 @@
+fn main() {
+	{
+		println('(1/3) My first small scope')
+		//
+	}
+
+	println('hello')
+}

vlib/v/parser/parser.v

@@ -1026,7 +1026,7 @@ fn (mut p Parser) stmt(is_top_level bool) ast.Stmt {
 				}
 			} else {
 				stmts := p.parse_block()
-				pos.last_line = p.prev_tok.line_nr
+				pos.update_last_line(p.prev_tok.line_nr)
 				return ast.Block{
 					stmts: stmts
 					pos:   pos