Add upper bound on th-sugar

@snoyberg this build plan checks out.

build-constraints.yaml

@@ -100,7 +100,10 @@ packages:
         - criterion
         - th-lift
         - singletons
-        - th-desugar
+
+        # https://github.com/fpco/stackage/issues/433
+        - th-desugar < 1.5
+
         - quickcheck-assertions
 
         - distributed-process-simplelocalnet