✅(e2e) e2e instances compatibility

We want to be able to run our e2e tests on
any instance of Docs, to do so we need to make
some adjustments to our tests and configuration.
We will use environment variables to configure
the tests.

src/frontend/apps/e2e/package.json

@@ -24,6 +24,7 @@
   "dependencies": {
     "@types/pngjs": "6.0.5",
     "convert-stream": "1.0.2",
+    "dotenv": "17.3.1",
     "pdf-parse": "2.4.5",
     "pixelmatch": "7.1.0",
     "pngjs": "7.0.0"