build(deps): bump net-smtp from 0.3.3 to 0.4.0

Bumps [net-smtp](https://github.com/ruby/net-smtp) from 0.3.3 to 0.4.0.
- [Release notes](https://github.com/ruby/net-smtp/releases)
- [Changelog](https://github.com/ruby/net-smtp/blob/master/NEWS.md)
- [Commits](ruby/net-smtp@v0.3.3...v0.4.0)

---
updated-dependencies:
- dependency-name: net-smtp
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -203,7 +203,7 @@ GEM
       timeout
     net-scp (4.0.0)
       net-ssh (>= 2.6.5, < 8.0.0)
-    net-smtp (0.3.3)
+    net-smtp (0.4.0)
       net-protocol
     net-ssh (7.2.0)
     nio4r (2.5.9)