Merge pull request #5501 from jchia/xmonad

Reinstate xmonad, xmonad-contrib & xmonad-extras

build-constraints.yaml

@@ -780,7 +780,7 @@ packages:
         - hourglass-orphans
         - wai-slack-middleware
         - sysinfo
-        - xmonad-extras < 0 # ghc 8.10
+        - xmonad-extras
         - shelly
         - persistent-redis < 0 # GHC 8.4 via hedis
         - fakedata
@@ -1575,7 +1575,7 @@ packages:
         - darcs < 0
         # - idris # aeson https://github.com/idris-lang/Idris-dev/issues/4493
         - libffi
-        - xmonad-contrib < 0 # ghc 8.10
+        - xmonad-contrib
         - cairo < 0
         - glib < 0
         - gio < 0
@@ -2537,7 +2537,7 @@ packages:
         - stringsearch # for cgi
         - titlecase
         - X11
-        - xmonad < 0 # ghc 8.10
+        - xmonad
 
     "Mark Fine <mark.fine@gmail.com> @markfine":
         - postgresql-schema < 0 # via postgresql-simple