Return the make exit code for qmk compile and flash (#11402)

lib/python/qmk/cli/flash.py

@@ -81,7 +81,8 @@ def flash(cli):
         cli.log.info('Compiling keymap with {fg_cyan}%s', ' '.join(command))
         if not cli.args.dry_run:
             cli.echo('\n')
-            subprocess.run(command)
+            compile = subprocess.run(command)
+            return compile.returncode
 
     else:
         cli.log.error('You must supply a configurator export, both `--keyboard` and `--keymap`, or be in a directory for a keyboard or keymap.')