Merge pull request haskell#10893 from haskell/wip/recent-ghc-versions

ci: Use ghc-9.12.2 and ghc-9.6.7

Author: mergify[bot]

.github/workflows/validate.yml

@@ -60,10 +60,10 @@ jobs:
         # support, so the PR *must* have a changelog entry.
         ghc:
           [
-            "9.12.1",
+            "9.12.2",
             "9.10.1",
             "9.8.4",
-            "9.6.6",
+            "9.6.7",
             "9.4.8",
             "9.2.8",
             "9.0.2",