wezterm: better implemenation of set_by_os to avoid checking for os multiple times

dot_config/wezterm/functions.lua

@@ -5,11 +5,12 @@ local function get_os()
 end
 
 local function set_by_os(values)
-    local my_os = get_os()
-    if values[my_os] then return values[my_os] end
+    if values[MY_OS] then return values[MY_OS] end
     return values.others
 end
 
+MY_OS = get_os()
+
 return {
     set_by_os = set_by_os
 }

dot_config/wezterm/wezterm.lua

@@ -26,11 +26,12 @@ cfg.font_size = fn.set_by_os{
 }
 
 -- visuals
+-- maybe enable these back one day
+-- cfg.window_decorations = 'RESIZE'
+-- cfg.hide_tab_bar_if_only_one_tab = false
 cfg.native_macos_fullscreen_mode = false
-cfg.window_decorations = 'RESIZE'
 cfg.xcursor_theme = 'Adwaita'
 cfg.use_fancy_tab_bar = false
-cfg.hide_tab_bar_if_only_one_tab = false
 cfg.show_new_tab_button_in_tab_bar = false
 cfg.tab_max_width = 24
 cfg.window_padding = {