Upgrade enso to GraalVM for jdk 21

[Akirathan]

Fixes #7851

Pull Request Description

Upgrade to GraalVM JDK 21.

> java -version
openjdk version "21" 2023-09-19
OpenJDK Runtime Environment GraalVM CE 21+35.1 (build 21+35-jvmci-23.1-b15)
OpenJDK 64-Bit Server VM GraalVM CE 21+35.1 (build 21+35-jvmci-23.1-b15, mixed mode, sharing)

With SDKMan, download with sdk install java 21-graalce.

Important Notes

• After this PR, one can theoretically run enso with any JRE with version at least 21.
• Removed sbt bootstrap hack and all the other build time related hacks related to the handling of GraalVM distribution.
• project-manager remains backward compatible - it can open older engines with runtimes. New engines now do no longer require a separate runtime to be downloaded.
• sbt does not support compilation of module-info.java files in mixed projects - JDK9: Support module-info.java sbt/sbt#3368
  • Which means that we can have module-info.java files only for Java-only projects.
  • Anyway, we need just a single module-info.class in the resulting runtime.jar fat jar.
• runtime.jar is assembled in runtime-with-instruments with a custom merge strategy (sbt-assembly plugin). Caching is disabled for custom merge strategies, which means that re-assembly of runtime.jar will be more frequent.
• Engine distribution contains multiple JAR archives (modules) in component directory, along with runner/runner.jar that is hidden inside a nested directory.
• The new entry point to the engine runner is EngineRunnerBootLoader that contains a custom ClassLoader - to make sure that everything that does not have to be loaded from a module is loaded from runner.jar, which is not a module.
  • The new command line for launching the engine runner is in distribution/bin/enso
• Newest version of Frgaal (20.0.1) does not recognize --source 21 option, only --source 20.

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed, the GUI was tested when built using ./run ide build.

[JaroslavTulach]

This probably removes a way to build engine with Espresso - the documentation needs an update (at least) or the build script needs a fix.