feat: Serialize tag data in OLX for blocks (#34145)

cms/envs/common.py

@@ -129,6 +129,7 @@ from django.urls import reverse_lazy
 
 from lms.djangoapps.lms_xblock.mixin import LmsBlockMixin
 from cms.lib.xblock.authoring_mixin import AuthoringMixin
+from cms.lib.xblock.tagging.tagged_block_mixin import TaggedBlockMixin
 from xmodule.modulestore.edit_info import EditInfoMixin
 from openedx.core.djangoapps.theming.helpers_dirs import (
     get_themes_unchecked,
@@ -975,6 +976,7 @@ XBLOCK_MIXINS = (
     XModuleMixin,
     EditInfoMixin,
     AuthoringMixin,
+    TaggedBlockMixin,
 )
 XBLOCK_EXTRA_MIXINS = ()