refactor(ssr): remove ssrTransform line offset preservation

[hi-ogawa]

Description

Partially revert #19004 to remove line offset preservation logic as a minor simplification. This is not necessary anymore on Vitest after vitest-dev/vitest#7557 and this transform was also a best effort basis and didn't cover all scenarios (e.g. comments and exports in between).

[hi-ogawa]

/ecosystem-ci run

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/vite@19829

commit: 281b797

[vite-ecosystem-ci]

📝 Ran ecosystem CI on 281b797: Open

suite	result	latest scheduled
vite-environment-examples	✅ success	❌ failure
storybook	❌ failure	❌ failure
vite-plugin-react	❌ failure	❌ failure
vike	✅ success	❌ failure
waku	✅ success	❌ failure

✅ laravel, marko, ladle, astro, quasar, nuxt, previewjs, analogjs, react-router, qwik, histoire, rakkas, vite-plugin-react-swc, vite-plugin-pwa, sveltekit, vite-plugin-cloudflare, unocss, vite-plugin-vue, vite-plugin-svelte, vite-setup-catalogue, vuepress, vitest, vitepress

[sapphi-red]

I think we should wait merging this until next major as

• this would break older Vitest versions + Vite after this PR
• the next major is soon
• keeping this is a small burden