Revert AGP to 8.11.1 to allow F-Droid build

Author: lcacheux

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 java = "17"
 android-minSdk = "24"
 android-compileSdk = "36"
-agp = "8.13.0"
+agp = "8.11.1"
 compose-plugin="1.9.0"
 hilt = "2.57.1"
 kotlin = "2.1.21"