Use centos-9 to build the swt natives

Centos-8 is out of service and the container even does not build anymore
therefore we can't get any updates.

This changes the build to use Centos 9 for building instead.

Jenkinsfile

@@ -24,7 +24,7 @@ kind: Pod
 spec:
   containers:
   - name: "swtbuild"
-    image: "eclipse/platformreleng-centos-swt-build:8"
+    image: "eclipse/platformreleng-centos-swt-build:9"
     imagePullPolicy: "Always"
     resources:
       limits: