Disable test isolation

Isolation isn't required and it takes the setup contribution to our
tests down from over 60 seconds to single figures, greatly speeding up
the tests.

GitOrigin-RevId: 72516e420583fa2dfcef13f2cc50b0769a100baf

services/web/vitest.config.js

@@ -8,5 +8,6 @@ module.exports = defineConfig({
     ],
     setupFiles: ['./test/unit/vitest_bootstrap.mjs'],
     globals: true,
+    isolate: false,
   },
 })