Add support for compiling against JDK 23+

[xroberx]

Now that gradle 8.14 is out with support for Java 24, it would be great to be able to compile Recaf with JDK 24. Currently it fails in:

Execution failed for task ':recaf-ui:compileJava'.
> Compilation failed; see the compiler output below.
  warning: unknown enum constant Level.FULL
    reason: class file for com.google.j2objc.annotations.ReflectionSupport$Level not found
  D:\Temp\Recaf\recaf-ui\src\main\java\software\coley\recaf\util\SVG.java:114: warning: [deprecation] load(@org.jetbrains.annotations.NotNull InputStream) in SVGLoader has been deprecated
                                return loader.load(is);
                                             ^
  D:\Temp\Recaf\recaf-ui\src\main\java\software\coley\recaf\util\SVG.java:35: error: cannot access NotNull
                                .load(new ByteArrayInputStream(("<svg width=\"0\" height=\"0\" xmlns=\"http://www.w3.org/2000/svg\">" +
                                ^
    class file for org.jetbrains.annotations.NotNull not found
  1 error
  3 warnings

[Col-E]

Renamed since the issue is actually for compiling in the context of people in nix/aur environments. Existing builds of Recaf run fine in JDK 23/24.

[xroberx]

Renamed since the issue is actually for compiling in the context of people in nix/aur environments. Existing builds of Recaf run fine in JDK 23/24.

Hi Matt,

Actually, the error I posted happens on Windows 11.

Best regards,
Robert.

[Col-E]

I used Windows 11

I was mainly referring to people in the discord who had also brought up the issue, along with similar requests in the past. Most people do not have a reason to change the version of Java or Gradle Recaf is compiled against. End users are intended to receive the Recaf jar compiled against Java 22. Running with a higher version works, but when somebody chooses to change the version of Java Recaf compiles against this problem occurs.