Remove outdated note on Java 21 support

README.md

@@ -16,19 +16,6 @@
 * [jdk21-alpine](https://github.com/keeganwitt/docker-gradle/blob/master/jdk21-alpine/Dockerfile)
 * [jdk21-graal](https://github.com/keeganwitt/docker-gradle/blob/master/jdk21-graal/Dockerfile)
 
-### Java 21 support
-
-Gradle currently has incomplete support for Java 21. The [8.4 release notes](https://docs.gradle.org/8.4/release-notes.html#java-21) say
-
-> Gradle now supports using Java 21 for compiling, testing, and starting other Java programs. This can be accomplished by configuring your build or task to use a Java 21 [toolchain](https://docs.gradle.org/8.4/userguide/toolchains.html).
->
-> You cannot currently run Gradle on Java 21 because Kotlin lacks support for JDK 21. However, you can expect support for running Gradle with Java 21 in a future version.
-
-This is also noted in the [compatibility guide](https://docs.gradle.org/current/userguide/compatibility.html).
-This means that you can't use Gradle with Java 21 with Kotlin DSL buildscripts, only Groovy DSL scripts.
-
-This means things like using the [`kotlin-dsl` plugin](https://docs.gradle.org/current/userguide/kotlin_dsl.html#sec:kotlin-dsl_plugin) in a buildSrc script aren't currently supported. The only way to run such projects for Java 21 is to launch Gradle with another JVM (8, 11, or 17) and then use Java 21 in a toolchain (requiring an image with both JVMs installed). This image doesn't exist currently. If this is something you need, please upvote [this PR](https://github.com/keeganwitt/docker-gradle/pull/265#issue-1938848965).
-
 ## What is Gradle?
 
 [Gradle](https://gradle.org/) is a build tool with a focus on build automation and support for multi-language development. If you are building, testing, publishing, and deploying software on any platform, Gradle offers a flexible model that can support the entire development lifecycle from compiling and packaging code to publishing websites. Gradle has been designed to support build automation across multiple languages and platforms including Java, Scala, Android, C/C++, and Groovy, and is closely integrated with development tools and continuous integration servers including Eclipse, IntelliJ, and Jenkins.