[U] Theme: follow upstream

sauricat · sauricat · commit 8847b568d125 · 2024-03-26T04:12:06.000-04:00
diff --git a/themes/book b/themes/book
@@ -1 +1 @@
-Subproject commit 089eac3d151efc37c606d4ea70688282bc83bce2
+Subproject commit e877b8e867ae6351d07ee07b006d6c45ec2e6fe9
