fix: Specify compute api dynamically

[cbartz]

Applicable spec:

Overview

Specify compute api to be max 2.91

Rationale

• there is a bug with 2.96
• 2.92 requires public key in keypair calls

Juju Events Changes

n/a

Module Changes

openstack_cloud will check the max api version to use in a cached property, and use this version when creating the openstack connection

Library Changes

Checklist

• The charm style guide was applied.
• The contributing guide was applied.
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex).
• The changelog is updated with changes that affects the users of the charm.

[yanksyoon]

Could you attach the proof of the locally passing CI please? LGTM

[cbartz]

Could you attach the proof of the locally passing CI please? LGTM

@yanksyoon Here it is

[github-actions]

Test results for commit 8a32f7c

Test coverage for 8a32f7c

Wrote XML report to coverage/coverage.xml

Static code analysis report

Run started:2025-07-09 13:51:38.913072

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 2055
  Total lines skipped (#nosec): 2
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 1

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):

[github-actions]

TICS Quality Gate

✔️ Passed

github-runner-operator

All conditions passed

See the results in the TICS Viewer

The following files have been checked for this project

• github-runner-manager/src/github_runner_manager/openstack_cloud/openstack_cloud.py
• github-runner-manager/tests/unit/openstack_cloud/test_openstack_cloud.py
• tests/integration/helpers/openstack.py
• tests/integration/test_charm_runner.py

.github/workflows/tics.yaml / TICS / TICS GitHub Action

[cbartz]

We decided to remove the integration test test_runner_manager , as those tests are covered in other integration test and it prevented merging due to its flakiness.

I've adapted the test_charm_runner integration test to cover one test (spawning two runners)