ci: bump install-test uv container to pytorch 26.06-py3

The uv-test-pytorch job builds TransformerEngine from source (divergent dev TE pin) and its bundled nccl_ep fails to compile on 25.05-py3 (fatal error: nccl_device.h: No such file or directory). Bump to 26.06-py3 (matches docker/Dockerfile.ci base + the release wheel container) whose NCCL headers ship nccl_device.h and the newer device-comm symbols.

Signed-off-by: svcnemo-autobot <svcnemo-autobot@nvidia.com>

Author: svcnemo-autobot

.github/workflows/install-test.yml

@@ -127,7 +127,7 @@ jobs:
     runs-on: ${{ needs.pre-flight.outputs.runner_prefix }}-container
     name: UV - Python${{ matrix.python-version }} - AMD64/Linux - NGC PyTorch
     container:
-      image: nvcr.io/nvidia/pytorch:25.05-py3
+      image: nvcr.io/nvidia/pytorch:26.06-py3
     strategy:
       fail-fast: false
       matrix: