ConsumesAttribute when Request.ContentType is null

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Describe the bug

When I POST with `null` ContentType ConsumesAttribute passes the request through. According to comment in the sources this possibility was left open to let through GET requests in case the attribute applied to a whole controller.

### Expected Behavior

The attribute should not pass POST-requests with `null` ContentType.

### Steps To Reproduce

`ByteArrayContent` instance has `null` for ContentType header.

new HttpClient().PostAsync(url, new ByteArrayContent(new byte[] { 50, 51 }));

### Exceptions (if any)

_No response_

### .NET Version

8.0.203

### Anything else?

_No response_