tilt: 0.18.10 -> 0.20.5

(cherry picked from commit 2aa7662279727652dd326d5e7fc2a9aa50a73eef)

pkgs/applications/networking/cluster/tilt/default.nix

···
   /* Do not use "dev" as a version. If you do, Tilt will consider itself
     running in development environment and try to serve assets from the
     source tree, which is not there once build completes.  */
-  version = "0.18.10";
+  version = "0.20.5";
 
   src = fetchFromGitHub {
     owner  = "tilt-dev";
     repo   = pname;
     rev    = "v${version}";
-    sha256 = "sha256-SvvvHGR3UPyV61MaoFB68SaZKUT3ItYOPT1a7AddxlY=";
+    sha256 = "sha256-pUKKHrShED7yp5WSmHSbS+eiYs22Nm2/ouc2a8WYc38=";
   };
   vendorSha256 = null;