Embind: css::uno::Type should probably use sharing_policy::NONE

Given the reasoning in 0957ee9f5d "Embind: No need
for $query", those sharing_policies appear to be (solely) about upcasting of
those smart pointers, and css::uno::Type doesn't involve any class hierarchies,
so NONE ("no upcasting", in genericPointerToWireType in Emscripten's
src/embind/embind.js) appears to be the best match here.

Change-Id: I74b74d3c31cc17a7fd0a6d072160316e60884557
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/166160
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <stephan.bergmann@allotropia.de>

static/source/unoembindhelpers/PrimaryBindings.cxx

@@ -45,7 +45,7 @@ template <> struct emscripten::smart_ptr_trait<css::uno::Type>
     {
         return ptr.getTypeLibType();
     }
-    static sharing_policy get_sharing_policy() { return sharing_policy::INTRUSIVE; }
+    static sharing_policy get_sharing_policy() { return sharing_policy::NONE; }
     static css::uno::Type* share(typelib_TypeDescriptionReference* v)
     {
         return new css::uno::Type(v);