chore: upgrade to hocon 0.42.0

[zmstone]

Release version: v/e5.6.0

Summary

This is a breaking fix:
backslashes in triple-quote strings are values, but not escape sequence.
This change is considered to have limited impact because:

• EMQX 5.6 will be the first version to generate triple-quotes in cluster.hocon.
• Escaping in triple-quote strings were only needed for backslash itself.

PR Checklist

Please convert it to a draft if any of the following conditions are not met. Reviewers may skip over until all the items are checked:

• Added tests for the changes
• Added property-based tests for code which performs user input validation
• Changed lines covered in coverage report
• Change log has been added to changes/(ce|ee)/(feat|perf|fix|breaking)-<PR-id>.en.md files
• For internal contributor: there is a jira ticket to track this change
• Created PR to emqx-docs if documentation update is required, or link to a follow-up jira ticket
• Schema changes are backward compatible

Checklist for CI (.github/workflows) changes

• If changed package build workflow, pass this action (manual trigger)
• Change log has been added to changes/ dir for user-facing artifacts update

[zmstone]

@thalesmg thank you, fixed the typos.