fix: ensure Content-Type header priority in the CLI (#4242)

- Ensure the `Content-Type` header takes priority over the value set in the request body.
- Introduces `HoppRESTRequest` schema `v6` with `text/xml` added under the supported content types.

packages/hoppscotch-cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@hoppscotch/cli",
-  "version": "0.10.1",
+  "version": "0.10.2",
   "description": "A CLI to run Hoppscotch test scripts in CI environments.",
   "homepage": "https://hoppscotch.io",
   "type": "module",