Option for defining proxy environment variables (http_proxy & https_proxy) in pyproject.toml

[Nomiez]

Referring to Q&A entry #2732.

Feature:
Support for exporting http_proxy & https_proxy environment variables out of pdm.toml before running a pdm command like pdm install. An example for this could be how (rye)[https://rye-up.com/guide/config/#config-file] is handling it:

[proxy]
# the proxy to use for HTTP (overridden by the http_proxy environment variable)
http = "http://127.0.0.1:4000"
# the proxy to use for HTTPS (overridden by the https_proxy environment variable)
https = "http://127.0.0.1:4000"

For pdm this could be implemented by adding the two options:

• proxy.http
• proxy.https

But let me hear about your opionion on that. If desired I could also implement the feature by myself.

[Nomiez]

Issue: #2752