chore(deps) bump Zipkin to 1.3.0 (Kong#6936)

Zipkin 1.3.0 is totally backwards compatible with 1.2.0 but brings fixes
and new features.

Before this change can be merged,
* Kong/kong-plugin-zipkin#107 needs to be approved and merged,
* A new tag of the plugin needs to be published in the zipkin repo
* A new version of the zipkin plugin needs to be published in Luarocks

kong-2.3.3-0.rockspec

@@ -41,7 +41,7 @@ dependencies = {
   "lua-resty-ipmatcher == 0.6",
   -- external Kong plugins
   "kong-plugin-azure-functions ~> 1.0",
-  "kong-plugin-zipkin ~> 1.2",
+  "kong-plugin-zipkin ~> 1.3",
   "kong-plugin-serverless-functions ~> 2.1",
   "kong-prometheus-plugin ~> 1.1",
   "kong-proxy-cache-plugin ~> 1.3",