fix: edX Studio doesn't support third-party handler urls for XBlock <class 'xblock.internal.VideoBlockWithMixins'>

[DanielVZ96]

This warning is appearing 30 times during provisioning. It clutters logs and hinders dev experience (#32888).

I appears to be due to thirdparty being set as True here (is it correct to set it to True?):

edx-platform/xmodule/video_block/video_block.py

Lines 1212 to 1213 in e820162

	transcripts = {
	lang: self.runtime.handler_url(self, 'transcript', 'download', query="lang=" + lang, thirdparty=True)