Acount chip displaying in single acount mode (from unified inbox)

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 version

6.708

Where did you get the app from?

F-Droid

Android version

13

Device model

Pixel

Steps to reproduce

1. Go to unified inbox
2. click on a message
3. See an account chip

Expected behavior

Not to see an account chip in single account mode

Actual behavior

I only have one account, so do not want to see account pills in my message view, however as of #7004 when opening a message from the unified inbox i get a account chip. This is inconsistent with other folder views where i do not see the chip as i have isSingleAccountMode
https://github.com/thundernest/k-9/blob/40d7db53f457dbcd382d3ee82cc07fbfb62d26fc/app/ui/legacy/src/main/java/com/fsck/k9/ui/messagelist/MessageListFragment.kt#L160
Should not always return true if isUnifiedInbox the logic needs to be a bit more complicated

Logs

No response