Fix race condition in duplicate InstallPlan prevention

[joelanford]

Description of the change:

Move the listInstallPlans() call to after the muInstallPlan lock is acquired in ensureInstallPlan(). Previously, the check for existing install plans happened before acquiring the lock, which meant that worker 2 could check for install plans before worker 1 had a chance to create one, even with the lock in place.

This fixes the race condition by ensuring that the sequence is:

1. Worker 1 acquires lock
2. Worker 1 checks for existing install plans
3. Worker 1 creates new install plan (if needed)
4. Worker 1 releases lock
5. Worker 2 acquires lock
6. Worker 2 checks for existing install plans (now sees worker 1's)
7. Worker 2 reuses existing install plan
8. Worker 2 releases lock

Motivation for the change:

Without this fix, both workers could see no existing install plans before either acquired the lock, leading to duplicate install plans being created for the same subscription.

Architectural changes:

None

Testing remarks:

Reviewer Checklist

• Implementation matches the proposed design, or proposal is updated to match implementation
• Sufficient unit test coverage
• Sufficient end-to-end test coverage
• Bug fixes are accompanied by regression test(s)
• e2e tests and flake fixes are accompanied evidence of flake testing, e.g. executing the test 100(0) times
• tech debt/todo is accompanied by issue link(s) in comments in the surrounding code
• Tests are comprehensible, e.g. Ginkgo DSL is being used appropriately
• Docs updated or added to /doc
• Commit messages sensible and descriptive
• Tests marked as [FLAKE] are truly flaky and have an issue
• Code is properly formatted

[perdasilva]

/approve

[openshift-ci]

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[perdasilva]

Just saw #3682 solves this in the same way (and adds a unit test). Let's get that one down instead?

[joelanford]

Duplicate of #3682 , but that one has a really nice unit test! Closing this one.