Features

• core: add default inputs if not already set in variables (Loïc Mathieu)

Bug Fixes

• ui: ExecutionRoot marge issue (YannC)
• core: null label value can crash the executor (Loïc Mathieu)
• core: missing lombok annotation on new storage tasks (Ludovic DEHON)
• core: prevent flow validation from crashing (#3278) (brian-mulier-p)

Chores

• bump version to v0.15.6 (Florian Hussonnois)