Jenkinsfile: Enable arm64 and armhf OStree builds

Signed-off-by: Frédéric Dalleau <frederic.dalleau@collabora.com>

Jenkinsfile

@@ -183,11 +183,6 @@ def buildOStree(architecture, type, board, debosarguments = "", production = fal
 
 def buildOStreeImage(architecture, type, board, debosarguments = "", production = false) {
 
-    if (architecture in ["arm64", "armhf"]) {
-      println "Skipping ostree image for ${architecture}"
-      return
-    }
-
     stage("${architecture} ${type} ${board} OStree image build") {
         sh(script: """\
            cd ${PIPELINE_VERSION}/${architecture}/${type}; \