Use Session.notify when chaining nox sessions (#188)

Use [nox.sessions.Session.notify](https://nox.thea.codes/en/stable/config.html#nox.sessions.Session.notify)
instead of directly calling other nox session functions.

Should result in _slightly_ nicer log output from nox

Co-authored-by: Jonas Lundberg <jonas@5monkeys.se>

noxfile.py

@@ -41,7 +41,7 @@ def lint(session):
     session.run("isort", "--project=respx", *source_files)
     session.run("black", "--target-version=py36", *source_files)
 
-    check(session)
+    session.notify("check")
 
 
 @nox.session