Bump version to 2.31.0-beta.8

- Update app versionName for the v2.31.0-beta.8 release
- Keep versionCode derived from git history

🤖 Auto-generated

Author: OwenMcGirr

app/build.gradle.kts

@@ -20,7 +20,7 @@ android {
         minSdk = 29
         targetSdk = 36
         versionCode = gitVersionCode()
-        versionName = "2.31.0-beta.7"
+        versionName = "2.31.0-beta.8"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables {