Revert "Make reallyUnsafePtrEquality# levity-polymorphic"

This reverts commit d1f59540e8b7be96b55ab4b286539a70bc75416c.

This commit breaks the build of unordered-containers

```
[3 of 9] Compiling Data.HashMap.Internal.Array ( Data/HashMap/Internal/Array.hs, dist/build/Data/HashMap/Internal/Array.o, dist/build/Data/HashMap/Internal/Array.dyn_o )
*** Parser [Data.HashMap.Internal.Array]:
Parser [Data.HashMap.Internal.Array]: alloc=21043544 time=13.621
*** Renamer/typechecker [Data.HashMap.Internal.Array]:
Renamer/typechecker [Data.HashMap.Internal.Array]: alloc=151218672 time=187.083
*** Desugar [Data.HashMap.Internal.Array]:
ghc: panic! (the 'impossible' happened)
  GHC version 9.3.20210625:
	expectJust splitFunTy
CallStack (from HasCallStack):
  error, called at compiler/GHC/Data/Maybe.hs:68:27 in ghc:GHC.Data.Maybe
  expectJust, called at compiler/GHC/Core/Type.hs:1247:14 in ghc:GHC.Core.Type
```

Revert containers submodule update

1 files changed, 0 insertions, 0 deletions

diff --git a/libraries/containers b/libraries/containers
-Subproject f90e38cb170dcd68de8660dfd9d0e879921acc2
+Subproject 7fb91ca53b1aca7c077b36a0c1f8f785d177da3