itamae: update all gems to latest versions

pkgs/by-name/it/itamae/Gemfile.lock

···
     docker-api (2.4.0)
       excon (>= 0.64.0)
       multi_json
-    ed25519 (1.3.0)
+    ed25519 (1.4.0)
     excon (1.2.5)
       logger
     hashie (5.0.0)
···
     net-telnet (0.2.0)
     schash (0.1.2)
     sfl (2.3)
-    specinfra (2.92.0)
+    specinfra (2.94.0)
       base64
       net-scp
       net-ssh (>= 2.7)
···
   itamae
 
 BUNDLED WITH
-   2.6.2
+   2.6.6

pkgs/by-name/it/itamae/gemset.nix

···
     platforms = [ ];
     source = {
       remotes = [ "https://rubygems.org" ];
-      sha256 = "0zb2dr2ihb1qiknn5iaj1ha1w9p7lj9yq5waasndlfadz225ajji";
+      sha256 = "01n5rbyws1ijwc5dw7s88xx3zzacxx9k97qn8x11b6k8k18pzs8n";
       type = "gem";
     };
-    version = "1.3.0";
+    version = "1.4.0";
   };
   excon = {
     dependencies = [ "logger" ];
···
     platforms = [ ];
     source = {
       remotes = [ "https://rubygems.org" ];
-      sha256 = "0aswlmhh152c974i8bn8d90kjbwadp0bjgs9kgpxxb3vffsfxc1w";
+      sha256 = "1m7vplx6w0w0mmij6n7zgc68kd1xbkhyb4qg25vmk8p21nbjbw6j";
       type = "gem";
     };
-    version = "2.92.0";
+    version = "2.94.0";
   };
   thor = {
     groups = [ "default" ];