Remove ghc810 from nix flake and GHA

Author: aniketd

.github/workflows/haskell.yml

@@ -36,7 +36,7 @@ jobs:
   build:
     strategy:
       matrix:
-        ghc: ["8.10.7", "9.2.8", "9.6.7", "9.8.4", "9.10.1", "9.12.1"]
+        ghc: ["9.2.8", "9.6.7", "9.8.4", "9.10.1", "9.12.1"]
         os: [ubuntu-latest]
       fail-fast: false
 
@@ -213,7 +213,7 @@ jobs:
         - set-algebra
         - small-steps
         - vector-map
-        ghc: ["8.10.7", "9.2.8", "9.6.7", "9.8.4", "9.10.1", "9.12.1"]
+        ghc: ["9.2.8", "9.6.7", "9.8.4", "9.10.1", "9.12.1"]
         os: [ubuntu-latest]
       fail-fast: false