Remove rhino dependency

Author: danslapman

backend/build.sbt

@@ -76,7 +76,6 @@ val mockingbird = (project in file("mockingbird"))
       "com.github.geirolz"            %% "advxml-core"         % "2.5.1",
       "com.github.geirolz"            %% "advxml-xpath"        % "2.5.1",
       "io.estatico"                   %% "newtype"             % "0.4.4",
-      "org.mozilla"                    % "rhino"                         % "1.7.14",
       "org.graalvm.js"                 % "js"                            % "22.3.0",
       "org.slf4j"                      % "slf4j-api"           % "1.7.30" % Provided
     ),