Allow Security Field for Schema to be optional

[jysheng123]

Which issue(s) does this change fix?

#6428

Why is this change necessary?

As per the open API document here https://swagger.io/specification/, users are allowed to specify if they want their endpoint to be security optional, this is done by passing security in the spec as security: [{}], however previously, this was treated as an error and raises an exception when it should be treated as no authorizer being passed in.

How does it address the issue?

Checks the edge case and does not raise error when it occurs.

What side effects does this change have?

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[ramosbugs]

thank you for fixing this!