fix: use rust target triple for arch in install-dust

dust's GitHub releases are named with aarch64/x86_64 (Rust target
triples), not uname -m's arm64/x86_64, so installs on Apple Silicon
downloaded a 404 body and failed with a tar "Unrecognized archive
format" error.

dot_local/bin/executable_install-dust

@@ -10,7 +10,7 @@ VERSION=${VERSION:-1.2.6}
 DEST=${XDG_DATA_HOME}/apps/releases/${APP}
 
 main() (
-	URL=https://github.com/bootandy/dust/releases/download/v${VERSION}/dust-v${VERSION}-$(uname -m)-$(get_os).tar.gz
+	URL=https://github.com/bootandy/dust/releases/download/v${VERSION}/dust-v${VERSION}-$(get_arch)-$(get_os).tar.gz
 
 	extract_tarball "${URL}" "${DEST}/${VERSION}" "--strip-component 1"
 	set_current_link "${DEST}" "${VERSION}"
@@ -28,4 +28,18 @@ get_os() (
 	esac
 )
 
+# dust releases use Rust target triples, which differ from uname -m
+get_arch() (
+	case $(uname -m) in
+	x86_64*) echo x86_64 ;;
+	amd64*) echo x86_64 ;;
+	arm64*) echo aarch64 ;;
+	aarch64*) echo aarch64 ;;
+	*)
+		echo >&2 "unsupported architecture: $(uname -m)"
+		exit 1
+		;;
+	esac
+)
+
 main "${@}"