Delete Jenkinsfile (#4181)

Jenkinsfile

@@ -1,28 +0,0 @@
-pipeline {
-    agent any
-    tools {
-        gradle 'Gradle 7'
-        jdk 'Java 17'
-    }
-    options {
-        buildDiscarder(logRotator(artifactNumToKeepStr: '20'))
-    }
-    stages {
-        stage ('Build') {
-            steps {
-                sh 'git submodule update --init --recursive'
-                rtGradleRun(
-                    usesPlugin: true,
-                    tool: 'Gradle 7',
-                    buildFile: 'build.gradle.kts',
-                    tasks: 'clean build',
-                )
-            }
-            post {
-                success {
-                    archiveArtifacts artifacts: 'bootstrap/**/build/libs/Geyser-*.jar', fingerprint: true
-                }
-            }
-        }
-    }
-}