Fix T59062: Keyframed node properties stay linked after shading network duplication.

There is no reason not to duplicate Actions too here, especially when
Materials' Actions are pretty much impossible to edit from current UI
(afaik, DopeSheet editor does not has any way to change them?).

source/blender/editors/render/render_shading.c

@@ -526,7 +526,9 @@ static int new_material_exec(bContext *C, wmOperator *UNUSED(op))
 
 	/* add or copy material */
 	if (ma) {
-		ma = BKE_material_copy(bmain, ma);
+		Material *new_ma = NULL;
+		BKE_id_copy_ex(bmain, &ma->id, (ID **)&new_ma, LIB_ID_COPY_DEFAULT | LIB_ID_COPY_ACTIONS);
+		ma = new_ma;
 	}
 	else {
 		const char *name = DATA_("Material");