Issue title: client_credentials and authorization_code cannot be used simultaneously
 Issue body: In `UseSwaggerUI`  calling `OAuthUsePkce` makes the `client_secret` textbox disappear for all flows. It is therefore impossible to use client_credentials (which requires a client_secret) and authorization_code (which requires this field to be absent) at the same time.
 Comments: 
 Comment 0: We have same issue. seems its fixed here - https://github.com/swagger-api/swagger-ui/pull/8146
{'source': 'GithubIssues', 'repo_name_with_owner': 'swagger-api/swagger-ui', 'issue_id': 1384199729, 'repo_stars': 22526.0}