update protomatter to 1.6.1 (used for RGBMatrix)

dhalbert · dhalbert · commit c5bc59e692dd · 2023-09-07T08:32:21.000-04:00
diff --git a/lib/protomatter b/lib/protomatter
@@ -1 +1 @@
-Subproject commit ed2e7018718caebba2b7550517b556e7734357ef
+Subproject commit c9c1189e9d6200bb09bf4a87d84be9459cae481b
