Remove Jenkinsfile.

I decided to put this in the job on Jenkins instead.
Also this is kinda an excuse to do a push to see if the webhook works.

Jenkinsfile

@@ -1,19 +0,0 @@
-pipeline {
-    agent any
-
-    stages {
-        stage('Setup') {
-            steps {
-                sh 'git submodule update --init --recursive'
-                sh 'TMP=~/.cache/NuGet/ nuget restore'
-                sh 'engine/Tools/download_godotsharp.py'
-            }
-        }
-        stage('Build') {
-            steps {
-                sh './package_release_build.py -p windows mac linux --godot /home/pjbriers/builds_shared/godot --windows-godot-build /home/pjbriers/builds_shared/win --linux-godot-build /home/pjbriers/builds_shared/linux'
-                archiveArtifacts artifacts: 'release/*.zip'
-            }
-        }
-    }
-}