OZG-5021 move jenkinsfile to root

Jenkinsfile.admin

+pipeline {
+  agent {
+    node {
+      label 'ozgcloud-jenkins-build-agent'
+    }
+  }
+
+  environment {
+        BLUE_OCEAN_URL = "https://jenkins.infra.ozg-cloud.systems/job/alfa/job/${env.BRANCH_NAME}/${env.BUILD_NUMBER}/"
+        RELEASE_REGEX = /\d+.\d+.\d+/
+        SNAPSHOT_REGEX = /\d+.\d+.\d+-SNAPSHOT/
+        FAILED_STAGE = ""
+        SH_SUCCESS_STATUS_CODE = 0
+    }
+
+    options {
+        timeout(time: 1, unit: 'HOURS')
+        disableConcurrentBuilds()
+        buildDiscarder(logRotator(numToKeepStr: '5'))
+    }
+
+    // TODO check version
+    stage('build') {
+      steps {
+        script {
+          FAILED_STAGE=env.STAGE_NAME
+
+          dir('alfa-client') {
+            sh 'echo "registry=https://nexus.ozg-sh.de/repository/npm-proxy" >> ~/.npmrc'
+            sh 'echo "//nexus.ozg-sh.de/:_auth=amVua2luczprTSFnNVUhMVQzNDZxWQ==" >> ~/.npmrc'
+
+						sh 'npm cache verify'
+            sh 'npm install'
+
+            if (isReleaseBranch()) {
+              sh 'npm run ci-prodBuild-admin'
+            } else {
+              sh 'npm run ci-build-admin'
+            }
+          }
+        }
+      }
+    }
+}
+
+Boolean isReleaseBranch() {
+    return env.BRANCH_NAME == 'release'
+}
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