Silence a warning.

Author: Patrick Thomson

semantic-proto/semantic-proto.cabal

@@ -46,6 +46,7 @@ library
     -Wno-missed-specialisations
     -Wno-all-missed-specialisations
     -Wno-star-is-type
+    -Wno-missing-export-lists
   if (impl(ghc >= 8.8))
     ghc-options: -Wno-missing-deriving-strategies
   if (impl(ghc >= 8.10))