nix: bump just and add to common profile

nix/pkgs/just.nix

@@ -0,0 +1,24 @@
+{ rustPlatform
+, stdenv
+}:
+
+  rustPlatform.buildRustPackage rec {
+    name = "just-${version}";
+    version = "849cdcb37fb42feb5e8724ec9fb3b34027e0da4f";
+    src = builtins.fetchGit {
+      url = "https://github.com/casey/just.git";
+      rev = version;
+    };
+
+    cargoSha256 = "0awfq9fhcin2q6mvv54xw6i6pxhdp9xa1cpx3jmpf3a6h8l6s9wp";
+
+    doCheck = false;
+
+    meta = with stdenv.lib; {
+      description = "Just a command runner ";
+      homepage = https://github.com/casey/just;
+      license = licenses.unlicense;
+      maintainers = [ ];
+      platforms = platforms.all;
+    };
+  }