Use ninja -k option in CI

Some users of the OAI CI complain that since we build with -Werror, it
is difficult to see all warnings/errors and fix them, necessitating
multiple attempts at times to see all warnings. To allow them to see
more warnings, use ninja option -k10 to keep going after errors, and
show more errors at once.

docker/Dockerfile.build.ubuntu22

@@ -45,6 +45,7 @@ RUN /bin/sh oaienv && \
       -w USRP -t Ethernet \
       --build-e2 --cmake-opt -DXAPP_MULTILANGUAGE=OFF --cmake-opt -DKPM_VERSION=$KPM_VERSION --cmake-opt -DE2AP_VERSION=$E2AP_VERSION \
       --noavx512 \
+      --build-tool-opt -k10 \
       --cmake-opt -DCMAKE_C_FLAGS="-Werror" --cmake-opt -DCMAKE_CXX_FLAGS="-Werror" $BUILD_OPTION && \
     # Mainly to see if the sanitize option was perfectly executed
     echo "---- ldd on executables ----" && \