silent werror on ubuntu builds (#906)

Author: nicolasaunai

.github/workflows/cmake_ubuntu.yml

@@ -78,11 +78,11 @@ jobs:
         make -j2 && sudo make install && cd ../.. && rm -rf samrai
         cd ${{runner.workspace}}/build && rm -rf *
         cmake $GITHUB_WORKSPACE -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON --fresh \
-              -DCMAKE_BUILD_TYPE=RelWithDebInfo -Dasan=OFF \
+              -DCMAKE_BUILD_TYPE=Debug -Dasan=OFF \
               -DCMAKE_C_COMPILER_LAUNCHER=ccache \
               -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
               -DlowResourceTests=ON -DdevMode=ON -Dbench=ON \
-              -DCMAKE_CXX_FLAGS="-DPHARE_DIAG_DOUBLES=1 " -Dphare_configurator=ON
+              -DCMAKE_CXX_FLAGS="-O3 -DPHARE_DIAG_DOUBLES=1 " -Dphare_configurator=ON
 
     - name: Build
       working-directory: ${{runner.workspace}}/build