docs: Update the version history in the middleware page

[nuta]

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Make it clear that only Next.js 13.0.0 or newer support setting request headers in a middleware.

Bug

• [ ] Related issues linked using fixes #number
• [ ] Integration tests added
• [ ] Errors have a helpful link attached, see contributing.md

Feature

• [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
• [ ] Related issues linked using fixes #number
• [ ] Integration tests added
• [ ] Documentation added
• [ ] Telemetry added. In case of a feature if it's used or not.
• [ ] Errors have a helpful link attached, see contributing.md

Documentation / Examples

• [x] Make sure the linting passes by running pnpm lint
• [ ] The "examples guidelines" are followed from our contributing doc