Fix rules_nixpkgs sha256

Author: avdv

haskell/repositories.bzl

@@ -9,7 +9,7 @@ load(
 load(":private/ghc_ci.bzl", "ghc_default_version")
 
 _rules_nixpkgs_version = "0.11.1"
-_rules_nixpkgs_sha256 = "108f78082c4842639ccc13fa5ad70ce7a7440991443ca1d5b15726cadd964053"
+_rules_nixpkgs_sha256 = "2a555348d7f8593fca2bf3fc6ce53c5d62929de81b6c292e23f16c557c0ae45a"
 
 _rules_sh_version = "v0.4.0"
 _rules_sh_sha256 = "3243af3fcb3768633fd39f3654de773e5fb61471a2fae5762a1653c22c412d2c"