fix(github): fix the classes for hiding column headers

Signed-off-by: Matej Focko <me@mfocko.xyz>

github.user.css

@@ -2,7 +2,7 @@
 @name           GitHub
 @namespace      git.mfocko.xyz/mfocko/usercss
 @updateURL      https://git.mfocko.xyz/mfocko/usercss/raw/branch/main/github.user.css
-@version        1.7.11
+@version        1.7.12
 @description    Switch monospace font and hide clutter.
 @author         mfocko <me@mfocko.xyz>
 @preprocessor   stylus
@@ -94,11 +94,10 @@ domain("githubusercontent.com") {
             display: none;
         }
     }
-    
+
     if hide-description-of-board-columns {
-        .buxasC, .bVaayg, .VwkZl, .eTJVOt, .dWilAV, .iYtFrB, .haRXvJ,
-        .eUPYPv,
-        .fzxeh {
+        .Box-sc-g0xbh4-0 .kaLWYX, /* Default light */
+        .Box-sc-g0xbh4-0 .bZkptl, /* Default dark */ {
             display: none;
         }
     }