ci: turn meson warnings into errors

.github/workflows/unit_tests.sh

@@ -56,7 +56,7 @@ for phase in "${PHASES[@]}"; do
                 # The docs build is slow and is not affected by compiler/flags, so do it just once
                 MESON_ARGS+=(-Dman=true)
             fi
-            run_meson --werror -Dtests=unsafe -Dslow-tests=true -Dfuzz-tests=true "${MESON_ARGS[@]}" build
+            run_meson --fatal-meson-warnings -Dnobody-group=nogroup --werror -Dtests=unsafe -Dslow-tests=true -Dfuzz-tests=true "${MESON_ARGS[@]}" build
             ninja -C build -v
             meson test -C build --print-errorlogs
             ;;
@@ -71,7 +71,7 @@ for phase in "${PHASES[@]}"; do
                 # -Db_lundef=false: See https://github.com/mesonbuild/meson/issues/764
                 MESON_ARGS+=(-Db_lundef=false -Dfuzz-tests=true)
             fi
-            run_meson --werror -Dtests=unsafe -Db_sanitize=address,undefined "${MESON_ARGS[@]}" build
+            run_meson --fatal-meson-warnings -Dnobody-group=nogroup --werror -Dtests=unsafe -Db_sanitize=address,undefined "${MESON_ARGS[@]}" build
             ninja -C build -v
 
             export ASAN_OPTIONS=strict_string_checks=1:detect_stack_use_after_return=1:check_initialization_order=1:strict_init_order=1