Fix configuration of DNS servers via OpenStack

[jcmoore3]

Ensure DNS server addresses are parsed from the proper location of network_data.json

Fixes #5386

Proposed Commit Message

fix: Ensure proper configuration of DNS servers via OpenStack json network config

Ensure DNS server addresses are parsed from the proper location
of network_data.json and that the services entry is not propogated

Additional Context

Test Steps

Checklist

• [x] My code follows the process laid out in the documentation
• [ ] I have updated or added any unit tests accordingly
• [ ] I have updated or added any documentation accordingly

Merge type

• [x] Squash merge using "Proposed Commit Message"
• [ ] Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)

[github-actions[bot]]

Hello! Thank you for this proposed change to cloud-init. This pull request is now marked as stale as it has not seen any activity in 14 days. If no activity occurs within the next 7 days, this pull request will automatically close.

If you are waiting for code review and you are seeing this message, apologies! Please reply, tagging TheRealFalcon, and he will ensure that someone takes a look soon.

(If the pull request is closed and you would like to continue working on it, please do tag TheRealFalcon to reopen it.)

[jcmoore3]

Apologies that the CLA is taking so long. This needs to go through my company's internal open source approval process. I do not anticipate any issues, it just takes time. I'm hoping to have final internal approval this week.

[jcmoore3]

CLA signed, please let me know if anything else is required to get this moving. Change to github-cla-signers is in PR #5369.

[aciba90]

I have pushed rebasing main and adding a unit test.