Fix a Clang 13 warning

`-Wdeprecated-copy` found this copy-assignment operator, which it
complains about. Since it is just `= default`, we should be able to
remove both it and the default constructor, making the struct just its
data members.

CHANGELOG.md

@@ -9,6 +9,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Build
+- Compiler warning in clang-13 ([`#2613`](https://github.com/polybar/polybar/pull/2613))
 
 ## [3.6.0] - 2022-03-01
 ### Breaking

include/x11/tray_manager.hpp

@@ -40,9 +40,6 @@ class background_manager;
 class bg_slice;
 
 struct tray_settings {
-  tray_settings() = default;
-  tray_settings& operator=(const tray_settings& o) = default;
-
   alignment align{alignment::NONE};
   bool running{false};
   int rel_x{0};