update agent-base package to 6.0.2

[frankwallis]

resolves Protocol "https:" not supported. Expected "http:" error in Node.js v16
Fixes #126

[TooTallNate]

Hey @frankwallis, thanks for the PR! However, the current value of 6 is sufficient, you just need to upgrade your dependencies. Run yarn upgrade or whatever the upgrade command is for the package manager you are using.

[agalatan]

• I think this PR should be accepted. There is no way to safely update agent-base to 6.0.2 inside a https-proxy-agent@5.0.1. That fact that https-proxy-agent@5.0.1 pins agent-base@6.0.0 makes it impossible for people to fix this safely.

• I am trying to get around it via yarn resolutions, but it's very problematic in a large codebase, where https-proxy-agent of both old and new versions (and using old and new versions of agent-base) coexist.

• And people do report the issue:
  https://stackoverflow.com/a/71482233/6269024
  Use https for the API calls or allow setting the protocol microsoft/cognitive-services-speech-sdk-js#465