Add r2.9 release nightly tests to README (#9478)

Author: pgmoka

README.md

@@ -40,7 +40,7 @@ To install PyTorch/XLA nightly build in a new TPU VM:
 ```sh
 pip install --pre torch torchvision --index-url https://download.pytorch.org/whl/nightly/cpu
 # Edit `cp310-cp310` to fit your desired Python version as needed
-pip install 'torch_xla[tpu] @ https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.8.0.dev-cp310-cp310-linux_x86_64.whl' \
+pip install 'torch_xla[tpu] @ https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.9.0.dev-cp312-cp312-linux_x86_64.whl' \
   -f https://storage.googleapis.com/libtpu-wheels/index.html
 ```
 
@@ -259,32 +259,31 @@ GPU release builds and GPU/TPU nightly builds are available in our public GCS bu
 
 | Version | Cloud GPU VM Wheels |
 | --- | ----------- |
-| 2.7 (CUDA 12.6 + Python 3.9) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/cuda/12.6/torch_xla-2.7.0-cp39-cp39-manylinux_2_28_x86_64.whl` |
 | 2.7 (CUDA 12.6 + Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/cuda/12.6/torch_xla-2.7.0-cp310-cp310-manylinux_2_28_x86_64.whl` |
 | 2.7 (CUDA 12.6 + Python 3.11) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/cuda/12.1/torch_xla-2.5.0-cp311-cp311-manylinux_2_28_x86_64.whl` |
-| nightly (Python 3.9) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.8.0.dev-cp39-cp39-linux_x86_64.whl` |
-| nightly (Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.8.0.dev-cp310-cp310-linux_x86_64.whl` |
-| nightly (Python 3.11) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.8.0.dev-cp311-cp311-linux_x86_64.whl` |
-| nightly (CUDA 12.6 + Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/cuda/12.6/torch_xla-2.8.0.dev-cp310-cp310-linux_x86_64.whl` |
+| nightly (Python 3.11) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.9.0.dev-cp311-cp311-linux_x86_64.whl` |
+| nightly (Python 3.12) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.9.0.dev-cp312-cp312-linux_x86_64.whl` |
+| nightly (Python 3.13) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.9.0.dev-cp312-cp312-linux_x86_64.whl` |
 
 #### Use nightly build
 
-You can also add `yyyymmdd` like `torch_xla-2.8.0.devyyyymmdd` (or the latest dev version)
+You can also add `yyyymmdd` like `torch_xla-2.9.0.devyyyymmdd` (or the latest dev version)
 to get the nightly wheel of a specified date. Here is an example:
 
 ```
-pip3 install torch==2.8.0.dev20250423+cpu --index-url https://download.pytorch.org/whl/nightly/cpu
-pip3 install https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.8.0.dev20250423-cp310-cp310-linux_x86_64.whl
+pip3 install torch==2.9.0.dev20250423+cpu --index-url https://download.pytorch.org/whl/nightly/cpu
+pip3 install https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.9.0.dev20250423-cp310-cp310-linux_x86_64.whl
 ```
 
-The torch wheel version `2.8.0.dev20250423+cpu` can be found at https://download.pytorch.org/whl/nightly/torch/.
+The torch wheel version `2.9.0.dev20250423+cpu` can be found at https://download.pytorch.org/whl/nightly/torch/.
 
 <details>
 
 <summary>older versions</summary>
 
 | Version | Cloud TPU VMs Wheel |
 |---------|-------------------|
+| 2.7 (Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.7.0-cp310-cp310-manylinux_2_28_x86_64.whl` |
 | 2.6 (Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.6.0-cp310-cp310-manylinux_2_28_x86_64.whl` |
 | 2.5 (Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.5.0-cp310-cp310-manylinux_2_28_x86_64.whl` |
 | 2.4 (Python 3.10) | `https://storage.googleapis.com/pytorch-xla-releases/wheels/tpuvm/torch_xla-2.4.0-cp310-cp310-manylinux_2_28_x86_64.whl` |