test: skip prebuilding some fixtures that are not used in integration tests

Author: pieh

tests/prepare.mjs

@@ -24,6 +24,8 @@ const e2eOnlyFixtures = new Set([
   'cli-before-regional-blobs-support',
   'dist-dir',
   'middleware-i18n-excluded-paths',
+  'middleware-static-asset-matcher',
+  'middleware-subrequest-vuln',
   // There is also a bug on Windows on Node.js 18.20.6, that cause build failures on this fixture
   // see https://github.com/opennextjs/opennextjs-netlify/actions/runs/13268839161/job/37043172448?pr=2749#step:12:78
   'middleware-og',