chore: Remove `dummy` subproject

It is not necessary anymore

build.gradle.kts

@@ -22,9 +22,6 @@ dependencies {
     implementation(libs.guava)
     // Used in JsonGenerator.
     implementation(libs.gson)
-
-    // A dependency to the Android library unfortunately fails the build, which is why this is required.
-    compileOnly(project("dummy"))
 }
 
 kotlin {
@@ -120,4 +117,4 @@ publishing {
             }
         }
     }
-}
+}

dummy/build.gradle.kts

@@ -1,9 +0,0 @@
-plugins {
-    id("java")
-}
-
-java {
-    toolchain {
-        languageVersion.set(JavaLanguageVersion.of(11))
-    }
-}

dummy/src/main/java/android/os/Environment.java

@@ -1,9 +0,0 @@
-package android.os;
-
-import java.io.File;
-
-public final class Environment {
-    public static File getExternalStorageDirectory() {
-        throw new UnsupportedOperationException("Stub");
-    }
-}

settings.gradle.kts

@@ -1,5 +1,3 @@
-include("dummy")
-
 rootProject.name = "revanced-patches"
 
 buildCache {