Upgrade to Java 17
Depends on https://github.com/stevespringett/Alpine/pull/410
Note: The compilation target version is defined in Alpine (which is still 11 in master). This PR includes the necessary changes to build and run DT with compilation target 17.
Build failures are due to InaccessibleObjectExceptions in tests. This will be automatically resolved once https://github.com/stevespringett/Alpine/pull/410 is merged, which includes the necessary surefire arguments (https://github.com/stevespringett/Alpine/pull/410/commits/88b9762e9d170b12ac721baf2c0f6fb4dec5b5cd).
Alpine 2.0.1-SNAPSHOT has been pushed to OSSRH.
@stevespringett I'm going to interpret that as approval and merge this one myself now so that our CI builds continue to work ✌