Sort DB list when creating database.yaml config

What does this MR do?

Helm keys template function returns an unordered dictionary. At some cases, this is triggering a diff of the ConfigMap, since the ordering of the databases may have changed from what's currently configured on the existing ConfigMap.

An example of this can be found on this job where an unrelated change caused the gitlab-cny-webservice-git workload to be updated, because of a diff to it's related ConfigMap.

Using the sortAlpha function ensures the order is always the same and the database.yaml file remains consistent unless there is a value change.

Related issues

https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/23908

Closes: #4874 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.