torch_tpu: update pin to a9906ed1625cb904e370426795d3dc07cc1506b4 (#3014)

Author: cota

.github/ci_commit_pins/torch_tpu.txt

@@ -1 +1 @@
-4681800baf67fe1fd2d12787a153e5300062dd53
+a9906ed1625cb904e370426795d3dc07cc1506b4

.github/workflows/benchmark_tpu.yml

@@ -57,7 +57,7 @@ jobs:
         run: |
           source .venv/bin/activate
           # Use the latest PyTorch wheel known to work with TorchTPU.
-          uv pip install -U --pre "torch==2.14.0.dev20260701" --index-url https://download.pytorch.org/whl/nightly/cpu
+          uv pip install -U --pre "torch==2.14.0.dev20260707" --index-url https://download.pytorch.org/whl/nightly/cpu
 
       - name: Install Helion
         run: |

.github/workflows/test.yml

@@ -129,7 +129,7 @@ jobs:
             uv pip install -U "torch==${VERSION}.*" --index-url https://download.pytorch.org/whl/${{ matrix.runtime-version }}
           elif [[ "${{ matrix.runtime-version }}" == "tpu" ]]; then
             # Use the latest PyTorch wheel known to work with TorchTPU.
-            uv pip install -U --pre "torch==2.14.0.dev20260701" --index-url https://download.pytorch.org/whl/nightly/cpu
+            uv pip install -U --pre "torch==2.14.0.dev20260707" --index-url https://download.pytorch.org/whl/nightly/cpu
           else
             # Default to nightly
             # On OSDC, route nightly through the pypi-cache /whl proxy (deps stay reachable behind the egress firewall) and clear the cache index vars so it wins over the cache default; off OSDC PYPI_CACHE_WHL_URL is unset so we hit download.pytorch.org.