[BUG] Multiple oauth2 flows cause typescript-node generation syntax errors

[philip-ellis-sp]

Bug Report Checklist

• [x] Have you provided a full/minimal spec to reproduce the issue?
• [x] Have you validated the input using an OpenAPI validator (example)?
• [x] Have you tested with the latest master to confirm the issue still exists?
• [x] Have you searched for related issues/PRs?
• [x] What's the actual output vs expected output?

Description

When generating SDK code using the generate command, typescript-node implementation has syntax errors in the API code when there are two or more oauth2 flows defined in the securitySchema

openapi-generator version

java -jar openapi-generator-cli.jar version
6.0.1

OpenAPI declaration file content or url

components:
  securitySchemes:
    oauth2:
      type: oauth2
      description: simple authentication
      flows:
        clientCredentials:
          tokenUrl: https://oauth/token
          scopes: 
            all: 'access to all scopes'
        authorizationCode:
          authorizationUrl: https://oauth/authorize
          tokenUrl: https://oauth/token
          scopes: 
            all: 'access to all scopes'

full file can be found here: example-api.yaml

Generation Details

java -jar openapi-generator-cli.jar generate -i example-api.yaml -g typescript-node -o sdk

Steps to reproduce

after generating the source files, you will see the following in the defaultApi.ts:

    protected authentications = {
        'default': <Authentication>new VoidAuth(),
        'oauth2': new OAuth(),
        'oauth2': new OAuth(),
    }

which prevents tsc from being able to build the file.

Related issues/PRs

I have not found a related issue