fix ubuntu CI (#109)

Error info:
/usr/include/lldb/Utility/FileSpec.h: In member function ‘bool lldb_private::FileSpec::IsCaseSensitive() const’:
/usr/include/lldb/Utility/FileSpec.h:205:41: error: ‘is_style_posix’ was not declared in this scope
  205 |   bool IsCaseSensitive() const { return is_style_posix(m_style); }

Author: Shao-Ce SUN

.github/workflows/ci.yml

@@ -19,7 +19,9 @@ jobs:
 
     steps:
       - name: Install Ninja, LLVM, Clang and LLDB (Ubuntu)
-        run: sudo apt-get install -y ninja-build clang-format clang libclang-dev liblldb-dev lldb llvm-dev llvm
+        run: |
+          sudo apt-get install -y ninja-build clang-format clang libclang-dev liblldb-dev lldb llvm-dev llvm
+          echo "LLVM_CONFIG_PATH=$(llvm-config --cmakedir)" >> $GITHUB_ENV
         if: matrix.os == 'ubuntu-latest'
 
       - name: Checkout sources