Re-enabled tests for myers-diff (codedownio/myers-diff#13).

Author: alaendle

build-constraints.yaml

@@ -8514,7 +8514,6 @@ expected-test-failures:
     - xml-html-qq # 0.1.0.1
     - xmlgen # 0.6.2.2 https://github.com/skogsbaer/xmlgen/issues/6
     - functor-combinators # 0.4.1.3 https://github.com/mstksg/functor-combinators/issues/9
-    - myers-diff # 0.3.0.1 https://github.com/codedownio/myers-diff/issues/13
     - path # 0.9.6 https://github.com/commercialhaskell/stackage/issues/7503
 
     # Consistent test failures