Remove color-scheme declaration from root for dark mode support

Author: MrPunyapal

src/Illuminate/Mail/resources/views/html/themes/default.css

@@ -1,9 +1,5 @@
 /* Base */
 
-:root {
-    color-scheme: light dark;
-}
-
 body,
 body *:not(html):not(style):not(br):not(tr):not(code) {
     box-sizing: border-box;