skip type-of-html bench: at least initial 9.12.2 build it seemed to get stuck

we can try to re-enable later

build-constraints.yaml

@@ -9263,6 +9263,9 @@ skipped-benchmarks:
     - pandoc
     - git-annex
 
+    # runaway build?
+    - type-of-html
+
     # Maintainers who don't want to update benchmarks
     # Only re-enable if requested.
     ## @hvr https://github.com/fpco/stackage/issues/2538#issuecomment-304458844