Markdown backticks render unreadably

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

K-9 Mail

App version

11.1

Where did you get the app from?

Google Play

Android version

13

Device model

SM-A515U (Galaxy A51)

Steps to reproduce

If a message contains (markdown) bacticks, the enclosed text renders as a blank white box. In the attached screenshot, the source is in this style:

My organization has a lot of packages emitting the `_DeprecatedInstaller`=
 [warning](https://github.com/pypa/setuptools/blob/9cc2f5c05c333cd4cecd2c=
0d9e7c5e208f2a3148/setuptools/installer.py#L149C7-L149C27). They use `set=
up_requires` to get a setuptools plugin similar to PBR.  Pip is apparentl=
y choosing to install them with `setup.py install`.

This message was not written originally as an email, it was a forum post (specifially in this case, python.org's Discourse forum) and forwarded by that software as email to subscribers.

Expected behavior

backtick contents renders in some readable format, doesn't have to be constant-width code style.

Actual behavior

Logs

No response

Reproduce the issue on Android 13 with K-9 Mail 11.1 using the provided forwarded message containing inline backticks, then trace the Markdown and email rendering path. Done means backtick-enclosed text renders readably instead of as a blank white box; add a regression test if the relevant test location is identified.