chore: move keytar to loadSavedConnections VSCODE-450

[kmruiz]

Description

Try to move keytar loading into loadSavedConnections so it's only loaded once per migration.

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added
• I have signed the MongoDB Contributor License Agreement (https://www.mongodb.com/legal/contributor-agreement)

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)

[kmruiz]

@alenakhineika that was the tests that were failing also on my local, they don't seem to be flaky, but some change of behaviour when we moved keytar to loadSavedConnections:

https://github.com/mongodb-js/vscode/actions/runs/5798050950/job/15714958344?pr=574#step:9:1290

Any clue? I personally won't put much more effort on this if the fix of the tests are too complex, as this is going to be run theoretically once during the migration and later we can just remove these 3 lines of code.

I won't be too concerned about the performance impact of this, as people don't have thousands of connections to migrate, probably just less than 5/10 and the storages are going to be far slower than failing loading the module.

[alenakhineika]

We do want to ensure that we require keytar once per extension activation to provide an accurate telemetry for VSCode team. The CI failure that you experienced is not related to the code moving you did. This started to happen because of a new VSCode release between your PRs, that introduced DNS result order changes. I have merged a fix for this issue, so rebase from main to unblock your PR.