Force the spacecmd login when running "spacewalk-hostname-rename" (bsc#1229848)

[meaksh]

What does this PR change?

This PR forces spacewalk-hostname-rename to perform an explicit login to spacecmd in order to have an active session when running the "refreshing pillar data for minions" stage of this script.

There is an issue currently at refreshing pillar data for minions stage, which may lead to having a stuck execution when the "spacecmd" session is expired, as the call to "spacecmd" hides the login prompt, making the user to feel that the script is stuck while it is waiting for reading input credentials from the user (but not visible).

This PR, just performs the login to "spacecmd" explicitely, before this stage, so we know the session is active and the login prompt is not hidden.

GUI diff

No difference.

• DONE

Documentation

• No documentation needed: only internal and user invisible changes

• DONE

Test coverage

• No tests: user case not covered by tests

• DONE

Links

Issue(s): https://github.com/SUSE/spacewalk/issues/25163

• DONE

Changelogs

Make sure the changelogs entries you are adding are compliant with https://github.com/uyuni-project/uyuni/wiki/Contributing#changelogs and https://github.com/uyuni-project/uyuni/wiki/Contributing#uyuni-projectuyuni-repository

If you don't need a changelog check, please mark this checkbox:

• No changelog needed

If you uncheck the checkbox after the PR is created, you will need to re-run changelog_test (see below)

Re-run a test

If you need to re-run a test, please mark the related checkbox, it will be unchecked automatically once it has re-run:

• Re-run test "changelog_test"
• Re-run test "backend_unittests_pgsql"
• Re-run test "java_pgsql_tests"
• Re-run test "schema_migration_test_pgsql"
• Re-run test "susemanager_unittests"
• Re-run test "javascript_lint"
• Re-run test "spacecmd_unittests"

Before you merge

Check How to branch and merge properly!

[vzhestkov]

LGTM, but most probably it doesn't work in the container for the other reason (but it's out of scope of this fix for sure)