Support install from source for PyTorch 2.6 RC in UT (#12697)

* Support install from source for PyTorch 2.6 RC in UT

* Remove expecttest

.github/actions/llm/setup-llm-env/action.yml

@@ -29,6 +29,9 @@ runs:
         sed -i 's/"bigdl-core-xe-addons-21==" + CORE_XE_VERSION/"bigdl-core-xe-addons-21"/g' python/llm/setup.py
         sed -i 's/"bigdl-core-xe-esimd-21==" + CORE_XE_VERSION/"bigdl-core-xe-esimd-21"/g' python/llm/setup.py
 
+        pip uninstall bigdl-core-xe-all -y || true
+        sed -i 's/"bigdl-core-xe-all==" + CORE_XE_VERSION/"bigdl-core-xe-all"/g' python/llm/setup.py
+
         pip install requests
         if [[ ${{ runner.os }} == 'Linux' ]]; then
           bash python/llm/dev/release_default_linux.sh default false
@@ -45,6 +48,9 @@ runs:
         elif [[ ${{ inputs.extra-dependency }} == 'xpu_2.1' ]]; then
           pip install --upgrade --pre -i https://pypi.python.org/simple --force-reinstall "python/llm/dist/${whl_name}[xpu_2.1]" --extra-index-url https://pytorch-extension.intel.com/release-whl/stable/xpu/cn/ 
           pip install pytest expecttest
+        elif [[ ${{ inputs.extra-dependency }} == 'xpu_2.6' ]]; then
+          pip install --upgrade --pre -i https://pypi.python.org/simple --force-reinstall "python/llm/dist/${whl_name}[xpu_2.6]" --extra-index-url https://download.pytorch.org/whl/test/xpu
+          pip install pytest
         else
           if [[ ${{ runner.os }} == 'Linux' ]]; then
             pip install --upgrade --pre -i https://pypi.python.org/simple --force-reinstall "python/llm/dist/${whl_name}[all]" --extra-index-url https://download.pytorch.org/whl/cpu