ci: refs #7643 Reprepro SSH credentials

Jenkinsfile

@@ -40,7 +40,7 @@ pipeline {
                 sh 'mkdir -p output'
                 sh 'mv ../*.deb ../*.build ../*.buildinfo ../*.changes output'
 
-                stash includes: 'output/*.deb', name: 'debPackage'
+                stash includes: 'output', name: 'debuildOutput'
             }
         }
         stage('Reprepro') {
@@ -51,16 +51,19 @@ pipeline {
                 }
             }
             steps {
-                unstash 'debPackage'
+                unstash 'debuildOutput'
+                debFile = sh(script: 'ls output/*.deb', returnStdout: true).trim()
 
-                script {
+                withCredentials([sshUserPrivateKey(
+                    credentialsId: 'jenkins-agent',
+                    usernameVariable: 'user'
+                    keyFileVariable: 'identityFile'
+                )]) {
                     remote.name = 'reprepro'
                     remote.host = 'reprepro.reprepro'
-                    remote.user = 'root'
-                    remote.identityFile = '/home/jenkins/.ssh/id_ed25519'
                     remote.allowAnyHosts = true
-
-                    debFile = sh(script: 'ls output/*.deb', returnStdout: true).trim()
+                    remote.user = user
+                    remote.identityFile = identityFile
                 }
 
                 sshPut([