deps: the pin advances to the reviewed libavr, and the clock example is 6 B smaller

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -28,7 +28,7 @@ Presets cover attiny85/atmega328p in both libavr modes (generated and
 reflect); `ctest` runs the consteval battery over the BCD, the hours
 register's two formats, the weekday, the alarm registers each rate writes and
 the control and status write-backs, and holds the example to its stated size —
-**1468 B** on the mega328P and **1256 B** on the tiny85, byte-identical across
+**1462 B** on the mega328P and **1256 B** on the tiny85, byte-identical across
 the two modes. The legacy
 yazoalfa-based driver lives on the `master` branch.