refactor: use MakoService.render_template to remove deprecation warnings

from block code.

openedx/core/lib/license/wrapper.py

@@ -3,12 +3,12 @@ Code to wrap web fragments with a license.
 """
 
 
-def wrap_with_license(block, view, frag, context):  # pylint: disable=unused-argument
+def wrap_with_license(block, view, frag, context, mako_service):  # pylint: disable=unused-argument
     """
     In the LMS, display the custom license underneath the XBlock.
     """
     license = getattr(block, "license", None)  # pylint: disable=redefined-builtin
     if license:
         context = {"license": license}
-        frag.content += block.runtime.render_template('license_wrapper.html', context)
+        frag.content += mako_service.render_template('license_wrapper.html', context)
     return frag

openedx/core/lib/xblock_builtin/xblock_discussion/xblock_discussion/__init__.py

@@ -32,6 +32,7 @@ def _(text):
 
 @XBlock.needs('user')  # pylint: disable=abstract-method
 @XBlock.needs('i18n')
+@XBlock.needs('mako')
 class DiscussionXBlock(XBlock, StudioEditableXBlockMixin, XmlParserMixin):  # lint-amnesty, pylint: disable=abstract-method
     """
     Provides a discussion forum that is inline with other content in the courseware.
@@ -202,7 +203,8 @@ class DiscussionXBlock(XBlock, StudioEditableXBlockMixin, XmlParserMixin):  # li
             'login_msg': login_msg,
         }
 
-        fragment.add_content(self.runtime.render_template('discussion/_discussion_inline.html', context))
+        fragment.add_content(self.runtime.service(self, 'mako').render_template('discussion/_discussion_inline.html',
+                                                                                context))
         fragment.initialize_js('DiscussionInlineBlock')
 
         return fragment
@@ -212,7 +214,7 @@ class DiscussionXBlock(XBlock, StudioEditableXBlockMixin, XmlParserMixin):  # li
         Renders author view for Studio.
         """
         fragment = Fragment()
-        fragment.add_content(self.runtime.render_template(
+        fragment.add_content(self.runtime.service(self, 'mako').render_template(
             'discussion/_discussion_inline_studio.html',
             {'discussion_id': self.discussion_id}
         ))