[fix] don't install pyright twice and do some clean up

Pyright has been installed twice so far, once via `package.json` and once in the
test script via `npx --no-install`. Separating the type checks in the CI and on
the developer desktop is also not necessary.

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "searxng.org/devtools",
   "dependencies": {
-    "pyright": "^1.1.391"
+    "pyright": "^1.1.403"
   },
   "scripts": {
     "clean": "rm -Rf node_modules package-lock.json"