haskell.compiler.ghc964: drop

Latest 9.6.x minor release is 9.6.7, which is also in Stackage 22.44.

Thus, dropping according to the GHC Deprecation Policy.

pkgs/development/compilers/ghc/9.6.4.nix

@@ -1,4 +0,0 @@
-import ./common-hadrian.nix {
-  version = "9.6.4";
-  sha256 = "10bf25b8b07174fdd9868b5c0c56c17c0ef1edcb6247b4b864be933651bfd4c0";
-}

pkgs/top-level/haskell-packages.nix

@@ -198,24 +198,6 @@ in
         buildTargetLlvmPackages = pkgsBuildTarget.llvmPackages_15;
         llvmPackages = pkgs.llvmPackages_15;
       };
-      ghc964 = callPackage ../development/compilers/ghc/9.6.4.nix {
-        bootPkgs =
-          # For GHC 9.2 no armv7l bindists are available.
-          if stdenv.buildPlatform.isAarch32 then
-            bb.packages.ghc928
-          else if stdenv.buildPlatform.isPower64 && stdenv.buildPlatform.isLittleEndian then
-            bb.packages.ghc928
-          else
-            bb.packages.ghc924Binary;
-        inherit (buildPackages.python3Packages) sphinx;
-        # Need to use apple's patched xattr until
-        # https://github.com/xattr/xattr/issues/44 and
-        # https://github.com/xattr/xattr/issues/55 are solved.
-        inherit (buildPackages.darwin) xattr autoSignDarwinBinariesHook;
-        # Support range >= 11 && < 16
-        buildTargetLlvmPackages = pkgsBuildTarget.llvmPackages_15;
-        llvmPackages = pkgs.llvmPackages_15;
-      };
       ghc965 = callPackage ../development/compilers/ghc/9.6.5.nix {
         bootPkgs =
           # For GHC 9.2 no armv7l bindists are available.
@@ -555,11 +537,6 @@ in
         ghc = bh.compiler.ghc963;
         compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-9.6.x.nix { };
       };
-      ghc964 = callPackage ../development/haskell-modules {
-        buildHaskellPackages = bh.packages.ghc964;
-        ghc = bh.compiler.ghc964;
-        compilerConfig = callPackage ../development/haskell-modules/configuration-ghc-9.6.x.nix { };
-      };
       ghc965 = callPackage ../development/haskell-modules {
         buildHaskellPackages = bh.packages.ghc965;
         ghc = bh.compiler.ghc965;

pkgs/top-level/release-haskell.nix

@@ -68,7 +68,6 @@ let
     ghc928
     ghc948
     ghc963
-    ghc964
     ghc965
     ghc966
     ghc967