[COMMIT scylla-cluster-tests master] fix(integration-tests): remove `apt-get update`

[Commit Bot]

From: Israel Fruchter <fr...@scylladb.com>
Committer: Israel Fruchter <israel....@gmail.com>
Branch: master

fix(integration-tests): remove `apt-get update`

this command was introduced to make sure the installation
of `ss` command is working as expected, since the docker image comes
with empty apt cache.

since the code was refactored and we don't use `ss` to check for open
ports anymore, we can safely remove this part, since it's really
slowing the integration test, doing this update every test run.

---
diff --git a/unit_tests/conftest.py b/unit_tests/conftest.py
--- a/unit_tests/conftest.py
+++ b/unit_tests/conftest.py
@@ -111,7 +111,6 @@ def db_alternator_up():
logging.error("Error checking for scylla up normal: %s", details)
return False

- scylla.remoter.run('apt-get update')
wait.wait_for(func=db_up, step=1, text='Waiting for DB services to be up', timeout=120, throw_exc=True)
wait.wait_for(func=db_alternator_up, step=1, text='Waiting for DB services to be up alternator)',
timeout=120, throw_exc=True)