ci: Add "macOS arm64" task

[hebasto]

This PR adds "macOS arm64" task which creates a downloadable binary for macOS systems based on Apple M1.

The downloaded file on macOS M1:

% lipo -info ./Downloads/insecure_mac_arm64_gui
Non-fat file: ./Downloads/insecure_mac_arm64_gui is architecture: arm64

---

IMPORTANT NOTE

macOS M1 requires all binaries must be signed. To apply ad-hoc code signing to the downloaded insecure_mac_arm64_gui, run:

% codesign -s - ./Downloads/insecure_mac_arm64_gui  

[jarolrod]

the downloaded arm64 binary does not run. If you double click the binary from within the finder, the terminal will open up and you will see output such as:

xyz@23:34 ~ ₿ /Users/xyz/Downloads/insecure_mac_arm64_gui ; exit;
zsh: killed     /Users/xyz/Downloads/insecure_mac_arm64_gui

Saving session...
...copying shared history...
...saving history...truncating history files...
...completed.

[Process completed]

If you attempt to run the binary from the terminal you will see:

xyz@23:34 Downloads ₿ ./insecure_mac_arm64_gui 
zsh: killed     ./insecure_mac_arm64_gui

[GBKS]

tACK. Note that I could not test whether the page transitions animate more smoothly now, since this version of the application does not have any page transitions. We'll have to test what with the updates on #124.

@jarolrod see the note about signing at the bottom of the issue. After signing it worked for me.