self-hosted ci: more cores for omegah build

Author: cwsmith

.github/workflows/pr_comment_trigger_self_hosted.yml

@@ -93,7 +93,7 @@ jobs:
             -DCMAKE_CUDA_ARCHITECTURES="80" \
             -DKokkos_PREFIX=$kkbdir/install \
             -DBUILD_SHARED_LIBS=on
-          cmake --build $ohbdir -j 4 --target install
+          cmake --build $ohbdir -j 6 --target install
 
           #meshfields
           mfbdir=${workDir}/build-meshfields