Add aarch64 architecture
Obsidian offers arm64 packages (by just appending -arm64 to the file name).
Tested locally, works great.
To test, you can easily create the package yourself:
CARCH="aarch64" makepkg -scAL
Will generate the obsidian-1.6.7-1-aarch64.pkg.tar.xz
package file you can inspect.