RUSTSEC-2020-0016: net2 crate has been deprecated; use socket2 instead

[github-actions]

net2 crate has been deprecated; use socket2 instead

Details
Status	unmaintained
Package	net2
Version	0.2.34
URL	deprecrated/net2-rs@3350e38
Date	2020-05-01

The net2 crate has been deprecated
and users are encouraged to considered socket2 instead.

See advisory page for additional details.

[macisamuele]

This is a dependency used only for tests (by some one the crate dependencies).
As this is indirect, we have no control on it and more important this is only used for a test of a dependency we're not going to specifically plan effort on this.
More detailed view: macisamuele/jsonschema-equivalent#4 (comment)