Update tests for macos-arm64 and amd64.

Author: yuchenshi

test/scripts/install.bats

@@ -132,15 +132,15 @@ function should-use-standalone() {
 
 # macOS use homebrew but falls back to standalone when brew is unavailable then
 # to npm for unsupported architectures.
-@test "$SCRIPT_NAME: macos arm64 (no brew)" {
-  should-fallback-npm-brew "arm64"
-}
 @test "$SCRIPT_NAME: macos amd64 (no brew)" {
-  BREW_PATH= OS=macos ARCH=amd64 run "$SCRIPT" --dry-run
+  should-fallback-npm-brew "amd64"
+}
+@test "$SCRIPT_NAME: macos arm64 (no brew)" {
+  BREW_PATH= OS=macos ARCH=arm64 run "$SCRIPT" --dry-run
   [ "$status" -eq 0 ]
   [ "${lines[1]}" = "Homebrew not installed." ]
   [ "${lines[2]}" = "Falling back to standalone installation." ]
-  [ "${lines[3]}" = "Installing v$VERSION of the amd64 release from GitHub." ]
+  [ "${lines[3]}" = "Installing v$VERSION of the arm64 release from GitHub." ]
   [[ "${lines[-6]}" = "Standalone release has been installed"* ]]
 }
 @test "$SCRIPT_NAME: macos i386 (no brew)" {