[BACKEND] fix inconsistent use of DLLVM_ENABLE_ZSTD (triton-lang#6726)

see recent failures to build like
https://github.com/triton-lang/triton/actions/runs/14864637012/job/41738239612?pr=6586

Author: makslevental

.github/workflows/llvm-build.yml

@@ -136,6 +136,7 @@ jobs:
         -DLLVM_INSTALL_UTILS=ON
         -DLLVM_TARGETS_TO_BUILD="host;NVPTX;AMDGPU"
         -DLLVM_ENABLE_TERMINFO=OFF
+        -DLLVM_ENABLE_ZSTD=OFF
         llvm-project/llvm
 
         ninja -C llvm-project/build check-mlir install
@@ -296,15 +297,15 @@ jobs:
           ${{ github.workspace }}/llvm-*-${{ matrix.config.target-os }}-${{ matrix.config.arch }}.tar.gz
 
     - name: Azure Login
-      if: ${{ (github.repository == 'triton-lang/triton') }}
+      if: ${{ (github.repository == 'triton-lang/triton') && github.ref_name == 'llvm-head' }}
       uses: azure/login@v2
       with:
         client-id: ${{ secrets.AZURE_CLIENT_ID }}
         tenant-id: ${{ secrets.AZURE_TENANT_ID }}
         subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
 
     - name: Upload LLVM Artifacts to Azure
-      if: ${{ (github.repository == 'triton-lang/triton') }}
+      if: ${{ (github.repository == 'triton-lang/triton') && github.ref_name == 'llvm-head' }}
       shell: bash -el {0}
       run: |
         az storage blob upload --account-name oaitriton --auth-mode login --container-name public --file "${{ env.llvm_install_dir }}.tar.gz" --name "llvm-builds/${{ env.llvm_install_dir }}.tar.gz" --overwrite
@@ -313,7 +314,7 @@ jobs:
         echo "Blob URL: ${URL}"
 
     - name: Azure Logout
-      if: ${{ (github.repository == 'triton-lang/triton') }}
+      if: ${{ (github.repository == 'triton-lang/triton') && github.ref_name == 'llvm-head' }}
       run: |
         az logout
         az cache purge

.github/workflows/llvm-build/almalinux.Dockerfile

@@ -34,6 +34,7 @@ RUN cmake -GNinja -Bbuild \
   -DLLVM_ENABLE_TERMINFO=OFF \
   -DLLVM_INSTALL_UTILS=ON \
   -DLLVM_TARGETS_TO_BUILD="host;NVPTX;AMDGPU" \
+  -DLLVM_ENABLE_ZSTD=OFF \
   /source/llvm-project/llvm
 
 RUN ninja -C build install

.github/workflows/llvm-build/centos.Dockerfile

@@ -51,6 +51,7 @@ RUN cmake -GNinja -Bbuild \
   -DLLVM_ENABLE_TERMINFO=OFF \
   -DLLVM_INSTALL_UTILS=ON \
   -DLLVM_TARGETS_TO_BUILD="host;NVPTX;AMDGPU" \
+  -DLLVM_ENABLE_ZSTD=OFF \
   /source/llvm-project/llvm
 
 RUN ninja -C build install

scripts/build-llvm-project.sh

@@ -22,6 +22,7 @@ if [ -z "$CMAKE_ARGS" ]; then
               -DCMAKE_CXX_COMPILER=clang++
               -DLLVM_ENABLE_LLD=ON
               -DLLVM_OPTIMIZED_TABLEGEN=ON
+              -DLLVM_ENABLE_ZSTD=OFF
               -DLLVM_TARGETS_TO_BUILD="$LLVM_TARGETS"
               -DCMAKE_EXPORT_COMPILE_COMMANDS=1
               -DLLVM_ENABLE_PROJECTS="$LLVM_PROJECTS"