Android: Bump SDK to 36 and Gradle to 8.13

Starting August 31, 2025, targeting at least Android 15 (API level 35) will be required: https://support.google.com/googleplay/android-developer/answer/11926878
This commit sets the target SDK to API level 36 (Android 16), the latest available version.

Source/Android/app/build.gradle.kts

@@ -7,7 +7,7 @@ plugins {
 
 @Suppress("UnstableApiUsage")
 android {
-    compileSdkVersion = "android-34"
+    compileSdkVersion = "android-36"
     ndkVersion = "27.0.12077973"
 
     buildFeatures {
@@ -40,7 +40,7 @@ android {
     defaultConfig {
         applicationId = "org.dolphinemu.dolphinemu"
         minSdk = 21
-        targetSdk = 34
+        targetSdk = 36
 
         versionCode = getBuildVersionCode()