[BUG][csharp] Bearer token not added when using AccessToken configuration

[Magnuti]

Bug Report Checklist

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

Description

Using either of these two configurations does not set the Authorization: Bearer <access_token> header.

var configuration = new Configuration
{
    AccessToken = accessToken
}

var configuration = new Configuration
{
    ApiKeyPrefix = new Dictionary<string, string>
    {
        { "Authorization", "Bearer" }
    },
    ApiKey = new Dictionary<string, string>
    {
        { "Authorization", accessToken }
    }
}

But using DefaultHeaders seems to work. This is counter intuitive - the AccessToken configuration property should either be fixed or removed.

// This works but it is ugly
var configuration = new Configuration
{
    DefaultHeaders = new Dictionary<string, string>
    {
         { "Authorization", $"Bearer {accessToken}" }
    }
}

openapi-generator version

openapitools/openapi-generator-cli:latest

OpenAPI declaration file content or url

https://api.signicat.com/info/lookup/swagger/v1/swagger.json

Generation Details

docker run --rm --volume "${PWD}:/generated" openapitools/openapi-generator-cli generate \
    -i https://api.signicat.com/info/lookup/swagger/v1/swagger.json \
    -g csharp \
    -o /generated \
    --additional-properties=targetFramework=net8.0

Steps to reproduce

1. Run the docker command above
2. Set the authorization token either with the AccessToken configuration property or by the ApiKeyPrefix + ApiKey configuration properties.
3. Send a request
4. Inspect the request headers
5. See that Authorization: Bearer <access_token> is not present

Related issues/PRs

Suggest a fix

Remove the non-working configuration properties or fix them.