How to fix Flutter "Toolchain installation `usr/lib/jvm/java-21-openjdk` does not provide the required capabilities" error

I keep getting this warning on (Fedora) Linux when opening a Flutter project of mine inside VS Code. I changed JAVA_HOME and used flutter config --jdk-dir="/usr/lib/jvm/java-24-openjdk/ to change my Java version but it still keeps coming up with a warning referencing OpenJDK 21 (so before we even get to the question of the right java version, why is it stuck on version 21?):

The supplied phased action failed with an exception.
Could not create task ':app:compileDebugAndroidTestJavaWithJavac'.
Failed to calculate the value of task ':app:compileDebugAndroidTestJavaWithJavac' property 'javaCompiler'.
Toolchain installation '/usr/lib/jvm/java-21-openjdk' does not provide the required capabilities: [JAVA_COMPILER]

I even added org.gradle.java.home=/usr/lib/jvm/java-24-openjdk to android/gradle.properties.

This is the output of flutter doctor --verbose:

[✓] Flutter (Channel stable, 3.32.6, on Fedora Linux 41 (KDE Plasma) 6.15.5-100.fc41.x86_64, locale en_GB.UTF-8) [120ms]
    • Flutter version 3.32.6 on channel stable at /home/bitmapp3r/dev/flutter-sdk
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 077b4a4ce1 (6 days ago), 2025-07-08 13:31:08 -0700
    • Engine revision 72f2b18bb0
    • Dart version 3.8.1
    • DevTools version 2.45.1

[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [1,977ms]
    • Android SDK at /home/bitmapp3r/Android/Sdk
    • Platform android-36, build-tools 36.0.0
    • Java binary at: /usr/lib/jvm/java-17-openjdk/bin/java
      This JDK is specified in your Flutter configuration.
      To change the current JDK, run: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (Red_Hat-17.0.15.0.6-1) (build 17.0.15+6)
    • All Android licenses accepted.

[✓] Chrome - develop for the web [25ms]
    • Chrome at google-chrome

[✓] Linux toolchain - develop for Linux desktop [556ms]
    • clang version 19.1.7 (Fedora 19.1.7-4.fc41)
    • cmake version 3.30.8
    • ninja version 1.12.1
    • pkg-config version 2.3.0
    • OpenGL core renderer: AMD Radeon Graphics (radeonsi, renoir, ACO, DRM 3.63, 6.15.5-100.fc41.x86_64)
    • OpenGL core version: 4.6 (Core Profile) Mesa 25.0.7
    • OpenGL core shading language version: 4.60
    • OpenGL ES renderer: AMD Radeon Graphics (radeonsi, renoir, ACO, DRM 3.63, 6.15.5-100.fc41.x86_64)
    • OpenGL ES version: OpenGL ES 3.2 Mesa 25.0.7
    • OpenGL ES shading language version: OpenGL ES GLSL ES 3.20
    • GL_EXT_framebuffer_blit: yes
    • GL_EXT_texture_format_BGRA8888: yes

[✓] Android Studio (version 2025.1.1) [21ms]
    • Android Studio at /opt/android-studio
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13391695-b895.109)

[✓] VS Code (version unknown) [19ms]
    • VS Code at /usr/share/code
    • Flutter extension version 3.114.0
    ✗ Unable to determine VS Code version.

[✓] Connected device (3 available) [261ms]
    • SM S911B (mobile) • RFCX808ZYCE • android-arm64  • Android 15 (API 35)
    • Linux (desktop)   • linux       • linux-x64      • Fedora Linux 41 (KDE Plasma) 6.15.5-100.fc41.x86_64
    • Chrome (web)      • chrome      • web-javascript • Google Chrome 138.0.7204.100

[✓] Network resources [656ms]
    • All expected network resources are available.

• No issues found!

Here is my android/app/build.gradle.kts (I omitted the project name)

plugins {
    id("com.android.application")
    id("kotlin-android")
    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
    id("dev.flutter.flutter-gradle-plugin")
}

android {
    namespace = "com.example.x"
    compileSdk = flutter.compileSdkVersion
    ndkVersion = flutter.ndkVersion

    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_11
        targetCompatibility = JavaVersion.VERSION_11
    }

    kotlinOptions {
        jvmTarget = JavaVersion.VERSION_11.toString()
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId = "com.example.x"
        // You can update the following values to match your application needs.
        // For more information, see: https://flutter.dev/to/review-gradle-config.
        minSdk = flutter.minSdkVersion
        targetSdk = flutter.targetSdkVersion
        versionCode = flutter.versionCode
        versionName = flutter.versionName
    }

    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig = signingConfigs.getByName("debug")
        }
    }
}

flutter {
    source = "../.."
}