Rebase cloud-init to version 23.4
Jira: https://issues.redhat.com/browse/RHEL-18313
This rebases cloud-init to 23.4 bringing in tons of upstream fixes and making many of the previous backports from upstream unnecessary. This also gave us the opportunity to squash test fixes along with the corresponding code changes and simplify the history. Details are in the google doc here: https://docs.google.com/document/d/1m1YSndqSNMS4O_PQuZHFdO0jwM4BCQh-FUZT5lbzSa4/edit?usp=sharing
Pipeline is green with these changes.