Close files opened by hack helper commands

[buley]

Which issue this PR addresses:

Fixes #4708

What this PR does / why we need it:

This closes the files opened by hack/aead and hack/role once their read and parse paths complete. The hack/aead change keeps the existing stdin path untouched while cleaning up only real file opens.

Test plan for issue:

• go test ./hack/aead ./hack/role
• These helper packages do not currently carry focused unit tests, so the package compile check is the narrowest automated verification available here.

Is there any documentation that needs to be updated for this PR?

No. This is an internal resource-cleanup change in hack/.

How do you know this will function as expected in production?

The change only adds file cleanup after existing reads complete and does not alter CLI flags, parsing logic, or the data produced by either helper.

[openshift-ci]

Hi @buley. Thanks for your PR.

I'm waiting for a Azure member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work.

Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

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[Copilot]

Pull request overview

This PR addresses issue #4708 by ensuring short-lived helper commands under hack/ properly close any files they open during read/parse operations, avoiding unnecessary file descriptor leaks.

Changes:

• Add a deferred Close() for the manifest file opened by hack/role.
• Add best-effort closing for files opened by hack/aead when -file is not - (stdin remains untouched).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
hack/role/role.go	Defer-close the manifest file after opening it for parsing.
hack/aead/aead.go	Track and defer-close the opened input file when reading from a path instead of stdin.

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[buley]

Addressed the Copilot feedback in c1ae10766 by simplifying the hack/aead open/close flow and replacing the //nolint:errcheck close defers with explicit deferred wrappers.