[RTL] Do not add final newline to the paragraph context.

scene/gui/rich_text_label.cpp

@@ -547,7 +547,7 @@ float RichTextLabel::_shape_line(ItemFrame *p_frame, int p_line, const Ref<Font>
 				if (font_size_it && font_size_it->font_size > 0) {
 					font_size = font_size_it->font_size;
 				}
-				l.text_buf->add_string("\n", font, font_size);
+				l.text_buf->add_string(String::chr(0x200B), font, font_size);
 				txt += "\n";
 				l.char_count++;
 				remaining_characters--;