CI/CD - Fix Azure pipeline (#767)

**Description**
Azure pipeline cpu-unit-test failed for "2025-12-10T03:47:59.0628597Z
ERROR: Could not install packages due to an OSError: [Errno 28] No space
left on device"

**Root Cause**
This happens because the matrix jobs (Python 3.7, 3.10, 3.12) run in
parallel and share the same VM's disk. Python 3.12 downloads
newer/larger packages (especially PyTorch and NVIDIA CUDA libraries
which are ~3GB+), and when multiple jobs run simultaneously, they
exhaust the disk space.

**Fix**
Disable the cache usage when installing SB
Co-authored-by: Hongtao Zhang <hongtaozhang@microsoft.com>

.azure-pipelines/cpu-unit-test.yml

@@ -29,7 +29,7 @@ steps:
       if python3 -c "import sys; exit(0 if sys.version_info < (3, 11) else 1)"; then
         python3 -m pip install --upgrade setuptools==65.7
       fi
-      python3 -m pip install .[test,cpuworker]
+      python3 -m pip install --no-cache-dir .[test,cpuworker]
       make postinstall
     displayName: Install dependencies
   - script: |