refactor(e2e): use better dummy assets (#7536)

e2e/package.json

@@ -23,6 +23,7 @@
     "@types/luxon": "^3.4.2",
     "@types/node": "^20.11.17",
     "@types/pg": "^8.11.0",
+    "@types/pngjs": "^6.0.4",
     "@types/supertest": "^6.0.2",
     "@typescript-eslint/eslint-plugin": "^7.1.0",
     "@typescript-eslint/parser": "^7.1.0",
@@ -34,6 +35,7 @@
     "exiftool-vendored": "^24.5.0",
     "luxon": "^3.4.4",
     "pg": "^8.11.3",
+    "pngjs": "^7.0.0",
     "prettier": "^3.2.5",
     "prettier-plugin-organize-imports": "^3.2.4",
     "socket.io-client": "^4.7.4",