chore(build): remove relup_helper untar post hook for now

rebar.config

@@ -27,8 +27,7 @@
 {cover_export_enabled, true}.
 {cover_excl_mods, [emqx_exproto_pb, emqx_exhook_pb]}.
 
-{provider_hooks,[{pre,[{release,{relup_helper,gen_appups}}]},
-                 {post,[{release,{relup_helper,untar}}]}
+{provider_hooks,[{pre,[{release,{relup_helper,gen_appups}}]}
                 ]}.
 
 {post_hooks,[]}.