Add upper bounds for #2487 (graphviz).

Also remove some rogue white space.

build-constraints.yaml

@@ -4,11 +4,11 @@ packages:
     "Timo Koepke <timo.koepke@gmail.com> @koepket":
         - hinterface
 
-    "Jose Iborra <pepeiborra@gmail.com> @pepeiborra": 
+    "Jose Iborra <pepeiborra@gmail.com> @pepeiborra":
         - clr-marshal
         - clr-host
         # - clr-inline # https://github.com/fpco/stackage/pull/2470
-        
+
     "Joshua Koike <jkoike2013@gmail.com> @jano017":
         - discord-hs
 
@@ -3138,6 +3138,10 @@ packages:
 
         # https://github.com/fpco/stackage/issues/2481
         - megaparsec < 5.3.0
+
+        # https://github.com/fpco/stackage/issues/2487
+        - graphviz < 2999.19
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of