Strikethrough in markdown heading is not rendered in TOC entry

[jdheyburn]

What version of Hugo are you using (hugo version)?

$ hugo version
Hugo Static Site Generator v0.68.3-157669A0/extended darwin/amd64 BuildDate: 2020-03-24T12:11:24Z

Does this issue reproduce with the latest release?

Yes

Given a heading that contains strikethrough markdown, and TableOfContents is being rendered, the title of the heading does not reflect the strikethrough markdown - whereas it does for strong and italic markdown.

Example of markdown:
## Spice Up Your ~~Life~~ Python :snake:

Appears in ToC as below.

Whereas it is rendered fine as a heading.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. The resources of the Hugo team are limited, and so we are asking for your help.
If this is a bug and you can still reproduce this error on the master branch, please reply with all of the information you have about it in order to keep the issue open.
If this is a feature request, and you feel that it is still relevant and valuable, please tell us why.
This issue will automatically be closed in the near future if no further activity occurs. Thank you for all your contributions.

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.