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 - https://github.com/sbt/sbt/issues/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](https://github.com/enso-org/enso/pull/7991/files#diff-9ab172d0566c18456472aeb95c4345f47e2db3965e77e29c11694d3a9333a2aa) 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](https://github.com/enso-org/enso/pull/7991/files#diff-0b66983403b2c329febc7381cd23d45871d4d555ce98dd040d4d1e879c8f3725)
- [Newest version of Frgaal](https://repo1.maven.org/maven2/org/frgaal/compiler/20.0.1/) (20.0.1) does not recognize `--source 21` option, only `--source 20`.
* Enable log-to-file configuration
PR #7825 enabled parallel logging to a file with a much more
fine-grained log level by default.
However, logging at `TRACE` level on Windows appears to be still
problematic.
This PR reduced the default log level to file from `DEBUG` to `TRACE`
and allows to control it via an environment variable if one wishes to
change the verbosity without making code changes.
* PR comments
* Always log verbose to a file
The change adds an option by default to always log to a file with
verbose log level.
The implementation is a bit tricky because in the most common use-case
we have to always log in verbose mode to a socket and only later apply
the desired log levels. Previously socket appender would respect the
desired log level already before forwarding the log.
If by default we log to a file, verbose mode is simply ignored and does
not override user settings.
To test run `project-manager` with `ENSO_LOGSERVER_APPENDER=console` env
variable. That will output to the console with the default `INFO` level
and `TRACE` log level for the file.
* add docs
* changelog
* Address some PR requests
1. Log INFO level to CONSOLE by default
2. Change runner's default log level from ERROR to WARN
Took a while to figure out why the correct log level wasn't being passed
to the language server, therefore ignoring the (desired) verbose logs
from the log file.
* linter
* 3rd party uses log4j for logging
Getting rid of the warning by adding a log4j over slf4j bridge:
```
ERROR StatusLogger Log4j2 could not find a logging implementation. Please add log4j-core to the classpath. Using SimpleLogger to log to the console...
```
* legal review update
* Make sure tests use test resources
Having `application.conf` in `src/main/resources` and `test/resources`
does not guarantee that in Tests we will pick up the latter. Instead, by
default it seems to do some kind of merge of different configurations,
which is far from desired.
* Ensure native launcher test log to console only
Logging to console and (temporary) files is problematic for Windows.
The CI also revealed a problem with the native configuration because it
was not possible to modify the launcher via env variables as everything
was initialized during build time.
* Adapt to method changes
* Potentially deal with Windows failures
This change replaces Enso's custom logger with an existing, mostly off the shelf logging implementation. The change attempts to provide a 1:1 replacement for the existing solution while requiring only a minimal logic for the initialization.
Loggers are configured completely via `logging-server` section in `application.conf` HOCON file, all initial logback configuration has been removed. This opens up a lot of interesting opportunities because we can benefit from all the well maintained slf4j implementations without being to them in terms of functionality.
Most important differences have been outlined in `docs/infrastructure/logging.md`.
# Important Notes
Addresses:
- #7253
- #6739
