nixos/terminfo: remove broken package contour

Contour was broken for aarch64 in #253334, and completely broke
in #344788 for all platforms.

This removes the broken package, and adds a notice to remove broken
packages in the future. aarch64 users have waited a year for this to be
fixed, so I think we should lean to be more eager to remove in general,
and then the fix can come when it is ready, instead of letting it block
this.

Resolves: #258515
Signed-off-by: Christina Sørensen <christina@cafkafk.com>

nixos/modules/config/terminfo.nix

@@ -24,25 +24,35 @@
 
   config = {
 
+    # This should not contain packages that are broken or can't build, since it
+    # will break this expression
+    #
+    # Currently broken packages:
+    # - contour
+    #
     # can be generated with:
     # lib.attrNames (lib.filterAttrs
     #  (_: drv: (builtins.tryEval (lib.isDerivation drv && drv ? terminfo)).value)
     #  pkgs)
-    environment.systemPackages = lib.mkIf config.environment.enableAllTerminfo (map (x: x.terminfo) (with pkgs.pkgsBuildBuild; [
-      alacritty
-      contour
-      foot
-      kitty
-      mtm
-      rio
-      rxvt-unicode-unwrapped
-      rxvt-unicode-unwrapped-emoji
-      st
-      termite
-      tmux
-      wezterm
-      yaft
-    ]));
+    environment.systemPackages = lib.mkIf config.environment.enableAllTerminfo (
+      map (x: x.terminfo) (
+        with pkgs.pkgsBuildBuild;
+        [
+          alacritty
+          foot
+          kitty
+          mtm
+          rio
+          rxvt-unicode-unwrapped
+          rxvt-unicode-unwrapped-emoji
+          st
+          termite
+          tmux
+          wezterm
+          yaft
+        ]
+      )
+    );
 
     environment.pathsToLink = [
       "/share/terminfo"