UI: Delete Button for env vars does not work

[ipa-big]

Describe the bug
When creating a new service offering and loading env vars from .env/env.list file, deleting derived env vars does not work

To Reproduce
Steps to reproduce the behavior, e.g.:

1. Create new service offering
2. Load env vars from .env/env.list
3. Try to delete derived env var
4. See error: delete button is disabled

Expected behavior
when loading env vars from .env/env.list i should be able to delete derived env vars.

Screenshots / Logs
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Environment (please complete the following information):
1.4.0-SNAPSHOT

[ipa-big]

As the docker compose workflow will be redesign for easier creation of docker-compose based workflows and the button is part of a shared component, working on this issue will be postponed