After upgrading to v2.7.0, generated code fails to compile when the spec uses security at the top level or operation level but does not define the corresponding entry in components/securitySchemes.

Minimal spec to reproduce:

openapi: "3.0.0"
info:
  title: Test
  version: 1.0.0
security:
  - api_key: []
paths:
  /hello:
    get:
      operationId: getHello
      responses:
        "200":
          description: ok

oapi-codegen -generate types,gin,strict-server -o gen.go -package api spec.yaml

Generated output:

const (
    Api_keyScopes apiKeyContextKey = "api_key.Scopes"
)

gen.go:20:16: undefined: apiKeyContextKey

The constant references apiKeyContextKey but the type definition type apiKeyContextKey string is never emitted.

Adding components/securitySchemes fixes it -- the type is generated correctly. But the tool should not produce uncompilable code for a spec that was previously accepted, wdyt?