Removes DO binding from Containers & Sandboces

[mikenomitch]

Summary

With ctx.exports we no longer need the binding. Removing it as the default for Containers + Sandboxes

TODO:

• Add changelog
• Look for more spots
• Test
• Change templates outside of this repo

Documentation checklist

• Is there a changelog entry (guidelines)? If you don't add one for something awesome and new (however small) — how will our customers find out? Changelogs are automatically posted to RSS feeds, the Discord, and X.
• The change adheres to the documentation style guide.

[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
/src/content/changelog/	@cloudflare/pm-changelogs, @cloudflare/pcx-technical-writing
/src/content/docs/containers/	@mikenomitch, @th0m, @cloudflare/pcx-technical-writing, @cloudflare/cloudchamber
/src/content/docs/sandbox/	@whoiskatrin, @ghostwriternr, @cloudflare/pcx-technical-writing, @cloudflare/ai-agents

[Rafiqroni3]

Summary

With ctx.exports we no longer need the binding. Removing it as the default for Containers + Sandboxes

TODO:

• Add changelog
• Look for more spots
• Test
• Change templates outside of this repo

Documentation checklist

• Is there a changelog entry (guidelines)? If you don't add one for something awesome and new (however small) — how will our customers find out? Changelogs are automatically posted to RSS feeds, the Discord, and X.
• The change adheres to the documentation style guide.