fix(apiserver-resources): ignore not-found errors during deletion

[mattisonchao]

Summary

• When deleting API server-backed resources, if the resource doesn't exist on the cloud API server, treat it as success instead of retrying indefinitely
• This now applies consistently to RoleBindings, ServiceAccounts, ServiceAccountBindings, APIKeys, Secrets, Workspaces, and FlinkDeployments
• This prevents the controller from getting stuck in an error loop during helm uninstall when the remote resource was already cleaned up

Test plan

• Reproduced with customer's 3-phase Helm install against a kind cluster with v0.18.0
• Verified helm uninstall pulsar-rolebindings --wait completes cleanly with this fix
• Verified RoleBindings that were never created remotely can still be deleted locally
• Added controller regression tests covering delete-time 404 handling for ServiceAccounts, ServiceAccountBindings, APIKeys, Secrets, Workspaces, and FlinkDeployments
• Verified the full repository test target with make test

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[github-actions]

@mattisonchao:Thanks for your contribution. For this PR, do we need to update docs?
(The PR template contains info about doc, which helps others know more about the changes. Can you provide doc-related info in this and future PR descriptions? Thanks)

[freeznet]

@copilot extend the similar logics to other apiserverconnection resources, such as serviceaccounts, serviceaccountbindings, etc.

[Copilot]

@copilot extend the similar logics to other apiserverconnection resources, such as serviceaccounts, serviceaccountbindings, etc.

Addressed in 5508bac. The branch already had the same not-found-on-delete behavior for ServiceAccounts and ServiceAccountBindings, so I added regression coverage for those controller deletion paths to lock it in and verify finalizer cleanup stays successful when the remote resource is already gone.

[freeznet]

@copilot currently we only handles 404 error when deletes rolebinding resources, but we need to handle the same 404 error when delete other apiserverconnection bind resources, such as serviceaccounts, serviceaccountbindings, etc.

[Copilot]

@copilot currently we only handles 404 error when deletes rolebinding resources, but we need to handle the same 404 error when delete other apiserverconnection bind resources, such as servicea...

Addressed in c8bd207. I applied the same delete-time 404 handling across the API-server-backed reconcilers and expanded regression coverage for ServiceAccount, ServiceAccountBinding, APIKey, Secret, Workspace, and FlinkDeployment deletion paths.