fix(astro): Adjust Sentry middleware for Astro 6

[github-actions]

Note

The pull request "fix(astro): Adjust Sentry middleware for Astro 6" was created by @Lms24 but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

This PR adjusts our Astro middleware to be compatible with Astro 6. It also adds an e2e test app for Astro 6 on the node adapter.

Changes:

• Cleaned up peer dependency range in package.json
• The middleware context object's properties changed. We need to access route manifest now via ctx.[Symbol.for('astro.pipeline')] instead of ctx.[Symbol.for('context.routes')]
• For now, I skipped our server island tests because there's still a bug in Astro 6.0.2 which causes server islands not to work correctly. Once this is fixed (I subscribed to the issue), we should be able to re-enable the test without any fails 🤞

[linear-code]

JS-1919

[Lms24]

man do I hate this workflow