github: Disable building lldb-mi in the scheduled cross builds

Latest git llvm-project has switched to requiring C++17, while
lldb-mi still is built in C++14 mode. This makes the scheduled builds
fail. Therefore, disable building lldb-mi for now in the scheduled
builds, until this has been fixed in the latest git main versions
of lldb-mi.

.github/workflows/build.yml

@@ -186,11 +186,12 @@ jobs:
           . /opt/llvm-mingw/versions
           echo Building llvm-project $LLVM_VERSION mingw-w64 $MINGW_W64_VERSION cpython-mingw $PYTHON_VERSION_MINGW
           cat /opt/llvm-mingw/versions >> $GITHUB_ENV
+          echo LLDB_MI_PARAMS=--disable-lldb-mi >> $GITHUB_ENV
       - uses: actions/checkout@v2
       - name: Build
         run: |
           sudo apt-get update && sudo apt-get install autoconf-archive ninja-build
-          ./build-cross-tools.sh /opt/llvm-mingw $(pwd)/install/llvm-mingw-${{matrix.arch}} ${{matrix.arch}} --with-python
+          ./build-cross-tools.sh /opt/llvm-mingw $(pwd)/install/llvm-mingw-${{matrix.arch}} ${{matrix.arch}} --with-python $LLDB_MI_PARAMS
           cd install
           zip -9rq ../llvm-mingw-${{matrix.arch}}.zip llvm-mingw-${{matrix.arch}}
       - uses: actions/upload-artifact@v2