Use createOrPatch for Issuer, not createOrUpdate

What does this MR do?

Use createOrPatch for Issuer, not createOrUpdate

As reported in #614 (closed), the Issuer object was reportedly being 'updated' in every reconcile loop despite no changes being made.

Here we use 'createOrPatch' on the Issuer instead of 'createOrUpdate'. This was the only place where 'createOrUpdate' was used, and was most likely a remnant due to unexpected behavior from 'createOrPatch' historically that appears to have been addressed. Using this function, there are no more logs of the Issuer being updated on each reconcile loop.

Closes #614 (closed)

Changelog: fixed

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.

Related issues

Closes #614 (closed)

Test plan

1. Build Operator manifest: task build_operator
2. Deploy Operator manifest: task deploy_operator
3. Watch the logs from the Operator Pod, confirming that there are no logs related to the Issuer being updated during each reconcile loop.