test: cover empty operation security override

[kriptoburak]

Description

Adds an OAS 3 authorization test for operation-level security: [] when global OAuth security exists.

Motivation and Context

OpenAPI lets an operation-level empty security array override root-level requirements. This test keeps request building from adding global authorization to explicitly public operations.

How Has This Been Tested?

• git diff --check
• npx --yes prettier@3.1.1 --check test/oas3/execute/authorization.js
• Full test suite not run because this temporary clone has no node_modules and the workspace has about 1 GiB free disk.

Screenshots (if appropriate):

N/A

Types of changes

• No code changes (changes to documentation, CI, metadata, etc)
• Dependency changes (any modification to dependencies in package.json)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[kriptoburak]

Rebased onto the current main branch at 8c3759fe013c3bfee57d8f078b2603ebc6acd801. git range-diff confirms the regression patch is unchanged.

Local validation:

• Focused authorization suite: 20 tests passed
• Full lint passed
• All UMD, CommonJS, and ES builds passed
• git diff --check passed

This remains a test-only change.