Add optional fields to metadata.yaml

[rpbritton]

Filed by @canonical/solutions-qa

Overview

Updates the optionality of endpoints in the charm metadata, including the providing endpoints. This is based on the deployment steps here.

Rationale

The default value of optional is false, which for these endpoints appears incorrect

Juju Events Changes

N/A

Module Changes

N/A

Library Changes

N/A

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)
• The docs/changelog.md is updated with user-relevant changes in the format of keep a changelog v1.1.0

[cbartz]

✅ Approved by APAC ninja - Safe metadata change marking non-essential integrations as optional. CI passed, already reviewed by team.