Voice message duration indicator doesn't fit in UI when using a custom font

### Steps to reproduce

1. Configure a custom font such as `monospace` in element desktop (without selecting a different font size etc..).
2. Send or receive a voice message
3. Look at the rendered voice message item

### What happened?


The duration indicator did flow over into the next line. That seems to be due to the width of the item being relative to the text size on the `` node and not relative to the size of the actual font used(?).

### What did you expect?

The size of the field should be relative to the size of the font in the field (up to a reasonable limit, e.g. the full width).

### Operating system

MacOS

### Application version

Element desktop 1.8.1

### How did you install the app?

https://packages.riot.im/desktop/install/macos/Element.dmg