Add sr.ht build for meson reduced builds.

This should help better catch configs that break our website emscripten
build.

.builds/openbsd.yml

@@ -16,6 +16,11 @@ tasks:
     meson setup build_meson_min --buildtype=release -Dsingle_threaded=true -Dnanbox=false -Ddynamic_modules=false -Ddocstrings=false -Dnet=false -Dsourcemaps=false -Dpeg=false -Dassembler=false -Dint_types=false -Dreduced_os=true -Dffi=false
     cd build_meson_min
     ninja
+- meson_reduced: |
+    cd janet
+    meson setup build_meson_reduced --buildtype=release -Dreduced_os=true
+    cd build_meson_reduced
+    ninja
 - meson_prf: |
     cd janet
     meson setup build_meson_prf --buildtype=release -Dprf=true