Drop old Jenkinsfile pipeline

We've moved to GitLab a while ago.

Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

Jenkinsfile

-pipeline {
-  environment {
-      release = "v2022dev1"
-      branch = "apertis/${release}"
-  }
-
-  agent any
-
-  stages {
-    stage("Update test binaries from packages") {
-      steps {
-        sshagent (credentials: [ "79a6e702-d0b5-423a-b8e2-8dcd0ab6d2aa" ] ) {
-          sh "echo Current release: ${release}"
-          sh "echo Current branch: ${branch}"
-          sh "${workspace}/updater.sh ${release} ${branch}"
-        }
-      }
-    }
-
-    stage("Cleanup") {
-      steps {
-        deleteDir()
-      }
-    }
-  }
-}