Try to use the gh specified by the launch script

ci/Jenkinsfile

@@ -79,7 +79,7 @@ pipeline {
                     echo "Getting Common Workspace for ${Machine}"
                     ws("${custom_workspace[machine]}/${env.CHANGE_ID}") {
                         properties([parameters([[$class: 'NodeParameterDefinition', allowedSlaves: ['built-in', 'Hercules-EMC', 'Hera-EMC', 'Orion-EMC', 'Gaea'], defaultSlaves: ['built-in'], name: '', nodeEligibility: [$class: 'AllNodeEligibility'], triggerIfResult: 'allCases']])])
-                        GH = sh(script: "which gh || echo '~/bin/gh'", returnStdout: true).trim()
+                        GH = sh(script: "env ${GH} || which gh || echo '~/bin/gh'", returnStdout: true).trim()
                         CUSTOM_WORKSPACE = "${WORKSPACE}"
                         sh(script: "mkdir -p ${CUSTOM_WORKSPACE}/RUNTESTS;rm -Rf ${CUSTOM_WORKSPACE}/RUNTESTS/*")
                         sh(script: """${GH} pr edit ${env.CHANGE_ID} --repo ${repo_url} --add-label "CI-${Machine}-Building" --remove-label "CI-${Machine}-Ready" """)