Fix for the JS concurrency issue

When the JS scripts are fairly expensive and they are executed from multiple threads, the exception pops up.
This pre-release contains a fix that adds a lock around the JS execution block.

If you are using macOS Catalina and later you may need to remove the quarantine attribute from the bits before you can use them
To do this, run the following:

$ sudo xattr -r -d com.apple.quarantine path/to/graalvm/folder/