fix: replace old config schemas for extensions and blueprints

to overcome a lot of warnings given during for example testing where
these extensions are used.

Signed-off-by: Hellgren Heikki <heikki.hellgren@op.fi>

plugins/techdocs/package.json

@@ -86,7 +86,8 @@
     "git-url-parse": "^15.0.0",
     "lodash": "^4.17.21",
     "react-helmet": "6.1.0",
-    "react-use": "^17.2.4"
+    "react-use": "^17.2.4",
+    "zod": "^3.25.76 || ^4.0.0"
   },
   "devDependencies": {
     "@backstage/cli": "workspace:^",