libfontconfig.so.1: undefined symbol: FT_Done_MM_Var

Debian 11 Bullseye (Build 4) has the following issue:

```
./AppRun: symbol lookup error: /usr/lib/x86_64-linux-gnu/libfontconfig.so.1: undefined symbol: FT_Done_MM_Var
```
Debian 11 Bullseye (Build 3) did __not__ have the issue.

How can it be that such things break from one build to the next?

I am so sick and tired of this kind of BS.

* https://github.com/probonopd/linuxdeployqt/issues/261
* https://github.com/probonopd/linuxdeployqt/issues/259

> Just confirming that the proposed fix of excluding libharfbuzz.so.0 and libfreetype.so.6 from the AppImage works for me as well to get my own AppImage of Peek run again on Arch.