Release 2.1.0

This version includes the following changes:

• For security reasons, the 'Interpreter' field has changed from a freeform field, to a dropdown field where the following options are allowed: python, python2, python3
• Gradle version has been updated to 7.4.2.
• Now uses a branch of rundeck-plugins/build-zip running on Gradle 5.6
• pl.allegro.tech.build.axion-release plugin updated to use 1.13.4
• Can be built with Java 11