chore(deps) bump kong-plugin-request-transformer from 1.2.x to 1.3.x (#…

…6542)

### Summary

#### Added

- Include the `type` function in template environment.
  Because headers may contain array elements such as duplicated headers,
  `type` is a useful function in these cases.

kong-2.2.0-0.rockspec

@@ -43,7 +43,7 @@ dependencies = {
   "kong-plugin-serverless-functions ~> 1.0",
   "kong-prometheus-plugin ~> 1.0",
   "kong-proxy-cache-plugin ~> 1.3",
-  "kong-plugin-request-transformer ~> 1.2",
+  "kong-plugin-request-transformer ~> 1.3",
   "kong-plugin-session ~> 2.4",
   "kong-plugin-aws-lambda ~> 3.5",
   "kong-plugin-acme ~> 0.2",