fix(ssr): handle uninitialized export access as undefined

[hi-ogawa]

Description

• Closes v6.3.3 ReferenceError: Cannot access '__vite_ssr_export_default__' before initialization #19929
• Closes Vitest with Vite 6.3.x regressed and started failing vitest-dev/vitest#7902

Export hoisting #18983 made an cyclic import handling to match better with esm (meaning valid cyclic imports are accepted and invalid ones are correctly rejected), but it turns out to be too strict for Vitest users which tends to import arbitrary files as first entry. The behavior change was too drastic for the patch release 6.3.3 at least, so in this PR, I added try/catch to make invalid exports to be fallback to undefined. Note that this should still make valid cyclic imports to work, which was the original motivation of #18983.

I confirmed provided reproductions are fixed with pr package (except there is a case like #19929 (comment), which is due to another fix #19841, so they are still expected to be addressed on user side).

On Vitest side, there might be more complicated scenarios with mocking, so I couldn't actually tell whether it's an cyclic imports issues. We'll revisit whether we should remove try/catch after investigating that further.

[pkg-pr-new]

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npm i https://pkg.pr.new/vite@19959

commit: adbfb90

[hi-ogawa]

/ecosystem-ci run

[vite-ecosystem-ci]

📝 Ran ecosystem CI on 0eb9080: Open

suite	result	latest scheduled
previewjs	✅ success	❌ failure
laravel	❌ failure	❌ failure
vike	✅ success	❌ failure
vitest	❌ failure	❌ failure

✅ analogjs, astro, ladle, histoire, qwik, quasar, react-router, marko, nuxt, vite-environment-examples, rakkas, unocss, sveltekit, vite-plugin-react-swc, vite-plugin-pwa, vite-plugin-react, vite-setup-catalogue, vite-plugin-cloudflare, vite-plugin-svelte, storybook, waku, vuepress, vitepress, vite-plugin-vue