chore(central): more cleanup

[RTann]

Description

• Clean validateV4DefsVersion

  • Create a validate closure to remove defer calls from loop
  • s/Errorf/Error

• Minor nits to handleZipContentsFromVulnDump and handleScannerDefsFile

• Updated tests and added a few fixes for failing tests

• https://github.com/stackrox/stackrox/pull/11212

• https://github.com/stackrox/stackrox/pull/11825

• https://github.com/stackrox/stackrox/pull/11836

• https://github.com/stackrox/stackrox/pull/11837

• https://github.com/stackrox/stackrox/pull/11841

• https://github.com/stackrox/stackrox/pull/11842

• https://github.com/stackrox/stackrox/pull/11843 <-- This

User-facing documentation

• [x] CHANGELOG update is not needed
• [x] Documentation is not needed

Testing

• [x] inspected CI results

Automated testing

• [x] contributed no automated tests

How I validated my change

CI