Changes

• e443b36: Added an option in Hardhat Network to allow mining blocks with the same timestamp

• c23a1ca: Added support for the http_proxy environment variable. When this variable is set, Hardhat will send its requests through the given proxy for things like JSON-RPC requests, mainnet forking and downloading compilers.

  We also removed support for the HTTP_PROXY and HTTPS_PROXY environment variables, since http_proxy is the most commonly used environment variable for this kind of thing. Those variables could only be used for downloading compilers.

  Finally, we also added support for no_proxy, which accepts a comma separated list of hosts or "*". Any host included in this list will not be proxied.

  Note that requests to "localhost" or "127.0.0.1" are never proxied.

• 6954665: Added support for sending batch requests through WebSocket to the Hardhat node (thanks @tenbits!)

• 6bf1673: Added a config validation for the number of optimizer runs used (thanks @konarshankar07!)