mystmd does not render `text/html` MIME-type for inline `{eval}` role

[bryanwweber]

Description

mystmd doesn't render the text/html MIME-type if it is present when the {eval} role is used. I produced an explainer/reproducer repository over here: https://github.com/bryanwweber/mystmd-mime-ignored-repro This is a significant (IMO) difference from the {glue:} role developed for JB1 and I really miss being able to style content when inserting it inline.

Proposed solution

@agoose77 suggested that the fix belonged in myst-theme on Discord:

I suspect the bug is that we always prefer AST children over the mime bundle (IE it's in myst theme). This is something we'll be fixing soon anyway with output parsing.

Additional notes

@rowanc1 suggested I create this issue on Discord 😄