test: Add singleton for tests

[lemaitre-aneo]

Motivation

Windows tests fails with an obscure error. This could be related to how ports are not reused.

Description

Create a singleton for http and grpc client to avoid consuming multiple ports per test.

Testing

[When applicable, detail the testing you have performed to ensure that these changes function as intended. Include information about any added tests.]

Impact

[Discuss the impact of your modifications on ArmoniK. This might include effects on performance, configuration, documentation, new dependencies, or changes in behaviour.]

Additional Information

[Any additional information that reviewers should be aware of.]

Checklist

• My code adheres to the coding and style guidelines of the project.
• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• I have thoroughly tested my modifications and added tests when necessary.
• Tests pass locally and in the CI.
• I have assessed the performance impact of my modifications.

[github-actions]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
1479	1249	84%	0%	🟢

New Files

No new covered files...

Modified Files

No covered modified files...

updated for commit: d9b5b4d by action🐍