FEAT: Expose Web Standard middleware

[wolfy1339]

Follow up to octokit/webhooks.js#1078

Describe the need

Currently, octokit only supports creating middleware for Node.js ,
but there are times when I want to use octokit in an environment other than Node.js .
This is not a big problem with runtimes that are compatible with Node.js, such as Deno and Bun,
Edge runtimes such as Cloudflare Workers may not offer Node.js compatibility.
Therefore, it is necessary to provide Middleware that uses WebStandard API (Request/Response).

SDK Version

No response

API Version

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Relevant log output

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Code of Conduct

• I agree to follow this project's Code of Conduct

[github-actions]

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