fix(nodejs-express-server): remove unused axios dependency (#20707)

Remove axios from package.mustache as it's not used in the starter build.
This eliminates potential security vulnerabilities (ReDos & SSRF) from
the dependency tree without affecting functionality.

Author: gus-costa

modules/openapi-generator/src/main/resources/nodejs-express-server/package.mustache

@@ -27,7 +27,6 @@
     "winston": "^3.2.1"
   },
   "devDependencies": {
-    "axios": "^0.19.0",
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",
     "eslint": "^5.16.0",