Generated OpenAPI docs overrides [Consumes] attribute through [FromForm]

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

When creating a form that is expecting an image to be uploaded via `[Consumes("multipart/form-data")],` the generated OpenAPI document will define the expected value as `application/x-www-form-urlencoded`.

Controller:
```csharp
[HttpPost]
[Consumes("multipart/form-data")]
public async Task> ImageToData(
[FromForm] IFormFile image)
{
...
```

Generated OpenAPI document:
```
...
"requestBody": {
"content": {
"application/x-www-form-urlencoded": {
"schema": {
...
```

### Expected Behavior

I expect the generated OpenAPI docs to correctly annotate the endpoint as a
"multipart/form-data"
endpoint, as opposed to an
"application/x-www-form-urlencoded"
endpoint.

### Steps To Reproduce

1. Create an AspNetCore API with generated OpenAPI documentation.
2. On a controller, add an endpoint with the [Consumes] attribute and a [FromForm] parameter.
3. Browse the generated OpenAPI document (e.g http://localhost:5211/openapi/v1.json)
4. Note the discrepancy between the Consumes attribute and the generated documentation.

### Exceptions (if any)

_No response_

### .NET Version

9.0.200

### Anything else?

ASP.NET Core: 9.0.2

`dotnet --info`

.NET SDK:
Version: 9.0.200
Commit: 90e8b202f2
Workload version: 9.0.200-manifests.b4a8049f
MSBuild version: 17.13.8+cbc39bea8

Runtime Environment:
OS Name: ubuntu
OS Version: 24.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/a46039/.asdf/installs/dotnet/9.0.200/sdk/9.0.200/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
Version: 9.0.2
Architecture: x64
Commit: 80aa709f5d

.NET SDKs installed:
9.0.200 [/home/a46039/.asdf/installs/dotnet/9.0.200/sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.2 [/home/a46039/.asdf/installs/dotnet/9.0.200/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.2 [/home/a46039/.asdf/installs/dotnet/9.0.200/shared/Microsoft.NETCore.App]

Other architectures found:
None

Environment variables:
Not set

global.json file:
Not found

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