Use sbuild during CI

.Jenkinsfile

@@ -1,22 +1,13 @@
 pipeline {
-    agent { label 'docker' }
+    agent { label 'sbuild' }
     stages {
         stage('Build Debian package') {
-            agent {
-                docker {
-                    image 'evolix/gbp:bullseye'
-                    args '-u root --privileged'
-                }
-            }
             when {
                 branch 'debian'
             }
             steps {
                 script {
-                    sh 'mk-build-deps --install --remove debian/control'
+                    sh 'gbp buildpackage'
-                    sh 'rm -rf {source,*.gz,*.bz2,*.xz,*.deb,*.dsc,*.changes,*.buildinfo,lintian.txt,.git}'
-                    sh "gbp clone --debian-branch=$GIT_BRANCH $GIT_URL source"
-                    sh 'cd source && git checkout $GIT_BRANCH && gbp buildpackage -us -uc'
                 }
                 archiveArtifacts allowEmptyArchive: true, artifacts: '*.gz,*.bz2,*.xz,*.deb,*.dsc,*.changes,*.buildinfo,lintian.txt'
             }