[ROCM] Remove docker, contrib ops, ci scripts related to ROCM EP (#26697)

### Description

This is follow up of #25181
to remove ROCM EP related files to avoid confusion.

Documents will be updated later.

### Motivation and Context

#26692

Author: tianleiwu

dockerfiles/Dockerfile.rocm

@@ -1,9 +1,8 @@
 # Dockerfiles
 **Execution Providers**
 - CPU: [Dockerfile](Dockerfile.source), [Instructions](#cpu)
-- CUDA/cuDNN: [Dockerfile](Dockerfile.cuda), [Instructions](#cuda)
+- CUDA: [Dockerfile](Dockerfile.cuda), [Instructions](#cuda)
 - MIGraphX: [Dockerfile](Dockerfile.migraphx), [Instructions](#migraphx)
-- ROCm: [Dockerfile](Dockerfile.rocm), [Instructions](#rocm)
 - OpenVINO: [Dockerfile](Dockerfile.openvino), [Instructions](#openvino)
 - TensorRT: [Dockerfile](Dockerfile.tensorrt), [Instructions](#tensorrt)
 - VitisAI: [Dockerfile](Dockerfile.vitisai)
@@ -304,17 +303,3 @@ Note: When running the container you built in Docker, please either use 'nvidia-
   ```
   docker run -it --device=/dev/kfd --device=/dev/dri --group-add video onnxruntime-migraphx
   ```
-
-   ## ROCm
-**Ubuntu 22.04, ROCm6.2.3**
-
-1. Build the docker image from the Dockerfile in this repository.
-  ```
-  docker build -t onnxruntime-rocm -f Dockerfile.rocm .
-  ```
-
-2. Run the Docker image
-
-  ```
-  docker run -it --device=/dev/kfd --device=/dev/dri --group-add video onnxruntime-rocm
-  ```