Comment out proxy cache in docs build to debug nvidia-sphinx-theme installation

Co-authored-by: leofang <5534781+leofang@users.noreply.github.com>

Author: Copilot

.github/workflows/build-docs.yml

@@ -52,9 +52,10 @@ jobs:
           fetch-depth: 0
           ref: ${{ inputs.git-tag }}
 
-      - name: Setup proxy cache
-        uses: nv-gha-runners/setup-proxy-cache@main
-        continue-on-error: true
+      # Temporarily disabled to debug nvidia-sphinx-theme installation issues
+      # - name: Setup proxy cache
+      #   uses: nv-gha-runners/setup-proxy-cache@main
+      #   continue-on-error: true
 
       - name: Set up miniforge
         uses: conda-incubator/setup-miniconda@835234971496cad1653abb28a638a281cf32541f  # v3.2.0