fix CI

set protobuf specific commit in requirements

.github/workflows/validate_operations.yml

@@ -2,6 +2,7 @@ name: Validate Operations
 
 env:
   LLVM_COMMIT: 0c2701fe7fa002e1befc5f86c268a7964f96d286
+  PROTOBUF_COMMIT: v34.0
 
 on:
   push:
@@ -20,7 +21,30 @@ jobs:
       - name: Install system dependencies
         run: |
           sudo apt update
-          sudo apt install -y cmake ninja-build build-essential protobuf-compiler
+          sudo apt install -y cmake ninja-build build-essential
+
+      - name: Cache protobuf build
+        id: cache-protobuf
+        uses: actions/cache@v4
+        with:
+          path: /usr/local
+          key: protobuf-${{ runner.os }}-${{ env.PROTOBUF_COMMIT }}
+
+      - name: Install protobuf
+        if: steps.cache-protobuf.outputs.cache-hit != 'true'
+        run: |
+          git clone --depth 1 --branch ${{ env.PROTOBUF_COMMIT }} https://github.com/protocolbuffers/protobuf
+          cd protobuf
+          mkdir build
+          cd build
+          cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Release
+          ninja
+          sudo ninja install
+          cd ../..
+          rm -rf protobuf
+
+      - name: Register installed libraries
+        run: sudo ldconfig
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@stable
@@ -33,11 +57,6 @@ jobs:
       - name: Install Python dependencies
         run: pip install numpy onnx colorama
 
-      - name: Clone LLVM
-        run: |
-          git clone -n https://github.com/llvm/llvm-project.git onnx-mlir/llvm-project
-          cd onnx-mlir/llvm-project && git checkout ${{ env.LLVM_COMMIT }}
-
       - name: Cache MLIR build
         id: cache-mlir
         uses: actions/cache@v4
@@ -45,6 +64,14 @@ jobs:
           path: onnx-mlir/llvm-project/build
           key: mlir-${{ runner.os }}-${{ env.LLVM_COMMIT }}
 
+      - name: Clone LLVM
+        if: steps.cache-mlir.outputs.cache-hit != 'true'
+        run: |
+          git clone --filter=blob:none --no-checkout https://github.com/llvm/llvm-project.git onnx-mlir/llvm-project
+          cd onnx-mlir/llvm-project
+          git fetch --depth 1 origin ${{ env.LLVM_COMMIT }}
+          git checkout FETCH_HEAD
+
       - name: Build MLIR
         if: steps.cache-mlir.outputs.cache-hit != 'true'
         run: |