`arch` returned by `coder_provisioner` and what `coder_agent` expects don't match

While running on a Raspberry Pi with armv7 architecture. A user reported this error. 
![image](https://github.com/coder/coder/assets/10648092/2a45f71a-47a2-41b4-a128-c744b8d5450e)

@bpmct could you try to reproduce on your Raspberry Pi?

Both workspace and Coder provisioner are running on Raspberry Pi. 

Manually changing `arch = armv7` for the `coder_agent` fixed the issue. 