github-assets-promote

[f1sh1918]

• add function to add assets (mainly copied from integreat)
• add function promote github release (mainly copied from integreat)
• set release notes param to optional and generate release note from github if not provided

needed for https://github.com/digitalfabrik/entitlementcard/issues/1165)and https://github.com/digitalfabrik/entitlementcard/issues/1232

[f1sh1918]

@maxammann is the app toolbelt used anywhere else than entitlementcard? since i adjusted some params

[f1sh1918]

i added a tag with recent main if sth breaks https://github.com/digitalfabrik/app-toolbelt/archive/refs/tags/v0.1.tar.gz