update qpcpp submodule to v8.1.2

mattheweshleman · mattheweshleman · commit 420f879d989b · 2026-01-08T09:46:34.000-06:00
diff --git a/externals/qpcpp b/externals/qpcpp
@@ -1 +1 @@
-Subproject commit fa83cb0dc85c25b40075a1685fd8a148b89b9b3a
+Subproject commit 1ed166adafcc7aca20ff6967f0dab89295c5c2d0
