fix(build-system-tests): remove undici resolutions, resolve to 6.27.0 (#7048)

Removes the exact-pin undici resolutions from e2e package.json that
blocked Dependabot from fixing 3 open alerts (GHSA-p88m-4jfj-68fv,
GHSA-g8m3-5g58-fq7m, GHSA-35p6-xmwp-9g52). undici now floats within
@actions/http-client's ^6.23.0 range and resolves to 6.27.0, which
patches all three advisories.

Author: bobbor

build-system-tests/e2e/package.json

@@ -28,8 +28,6 @@
   "resolutions": {
     "esbuild": "^0.25.0",
     "qs": "^6.15.2",
-    "undici": "6.24.0",
-    "@actions/http-client/undici": "6.24.0",
     "diff": "8.0.3",
     "serialize-javascript": "^7.0.5",
     "**/find-cypress-specs/minimatch": "^10.2.4",