remove stale stack yamls and bump 9.6.4

Author: nitinprakash96

.github/workflows/haskell-ci.yml

@@ -19,7 +19,7 @@ jobs:
         ghc:
           - 9.2.8
           - 9.4.8
-          - 9.6.4
+          - 9.6.6
           - 9.8.2
           - 9.10.1
     services:
@@ -64,7 +64,7 @@ jobs:
         stack-yaml:
           - stack-9.2.8.yaml
           - stack-9.4.8.yaml
-          - stack-9.6.4.yaml
+          - stack-9.6.6.yaml
           - stack-9.8.2.yaml
     services:
       postgres:

stack-8.10.7.yaml

@@ -0,0 +1 @@
+resolver: lts-22.36