Expect test failure for yggdrasil-schema per discussion in #7518

Signed-off-by: Mihai Maruseac <[email protected]>

build-constraints.yaml

@@ -8963,6 +8963,7 @@ expected-test-failures:
     - yarn-lock
     - yesod-gitrev # needs a git repo https://github.com/commercialhaskell/stackage/issues/6132
     - yesod-markdown # https://github.com/pbrisbin/yesod-markdown/issues/77
+    - yggdrasil-schema # https://github.com/commercialhaskell/stackage/issues/7518
 
     # Assertion failures due to module name ambiguity.
     # These _should_ be fixed by using the `hide` section of this file