sdk: update brew command

Co-authored-by: Ruby Iris Juric <[email protected]>

Author: griffinli

source/sdk/index.md

@@ -38,8 +38,7 @@ brew install python
 In addition, run:
 
 ```bash
-brew install glib
-brew install pixman
+brew install glib pixman
 ```
 
 #### Ubuntu