system: nixpkgs: update

modules/system/nix/nixpkgs.nix

@@ -1,34 +1,39 @@
 # taken from raf
 {
-  # Global nixpkgs configuration. This is ignored if nixpkgs.pkgs is set
-  # which is a case that should be avoided. Everything that is set to configure
-  # nixpkgs must go here.
+  # Global nixpkgs configuration.
+  # This is ignored if nixpkgs.pkgs is set, which should be avoided.
   nixpkgs = {
     # Configuration reference:
     # <https://nixos.org/manual/nixpkgs/unstable/#chap-packageconfig>
     config = {
-      # Disallow broken packages to be built.       allowBroken = false;
+      # Disallow broken packages to be built.
+      allowBroken = false;
+
       allowUnsupportedSystem = true;
 
+      # Warn when config contains an unrecognized attribute.
+      # This might be useful for getting a better configuration.
+      warnUndeclaredOptions = true;
+
       # Allow unfree packages
       allowUnfree = true;
 
-      # Default to none, add more as necessary. This is usually where
-      # electron packages go when they reach EOL.
-      permittedInsecurePackages = ["olm-3.2.16"];
+      # Permitted insecure packages in a system.
+      # Default to none, add more as necessary.
+      # Matrix also likes using deprecated libraries, which tend to go into this list.
+      # permittedInsecurePackages = [];
 
-      # Nixpkgs sets internal package aliases to ease migration from other
-      # distributions easier, or for convenience's sake. Even though the manual
-      # and the description for this option recommends this to be true, I prefer
-      # explicit naming conventions, i.e., no aliases.
+      # Whether to set enableParallelBuilding to true by default while
+      # building nixpkgs packages. Changing the default causes a mass rebuild.
+      enableParallelBuildingByDefault = false;
+
+      # Whether to expose old attribute names for compatibility.
+      # This improves backwards compatibility,
+      # which I could not care less about in my configuration.
       allowAliases = false;
 
       # List of derivation warnings to display while rebuilding.
       #  See: <https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/check-meta.nix>
-      # NOTE: "maintainerless" can be added to emit warnings
-      # about packages without maintainers but it seems to me
-      # like there are more packages without maintainers than
-      # with maintainers, so it's disabled for the time being.
       showDerivationWarnings = [];
     };
   };