Add GITHUB_ENV check

Author: sitaowang1998

components/core/tools/scripts/lib_install/macos/install-all.sh

@@ -48,15 +48,16 @@ brew install \
   xz \
   zstd
 
-echo "$GITHUB_ENV"
-LLVM_PREFIX=$(brew --prefix llvm@16)
-{
-  echo "LLVM_PREFIX=$LLVM_PREFIX"
-  echo "CC=$LLVM_PREFIX/bin/clang"
-  echo "CXX=$LLVM_PREFIX/bin/clang++"
-  echo "AR=$LLVM_PREFIX/bin/llvm-ar"
-  echo "RANLIB=$LLVM_PREFIX/bin/llvm-ranlib"
-} >> "$GITHUB_ENV"
+if [[ -n "${GITHUB_ENV}" ]]; then
+  LLVM_PREFIX=$(brew --prefix llvm@16)
+  {
+    echo "LLVM_PREFIX=$LLVM_PREFIX"
+    echo "CC=$LLVM_PREFIX/bin/clang"
+    echo "CXX=$LLVM_PREFIX/bin/clang++"
+    echo "AR=$LLVM_PREFIX/bin/llvm-ar"
+    echo "RANLIB=$LLVM_PREFIX/bin/llvm-ranlib"
+  } >> "$GITHUB_ENV"
+fi
 
 # Install pkg-config if it isn't already installed
 # NOTE: We might expect that pkg-config is installed through brew, so trying to install it again