fix: deprecated set-output in GitHub Action workflows

[tobiasehlert]

Due to deprecation of save-state and set-output commands in GitHub Action workflows, this PR should prevent workflows to fail after the 31st May 2023.

Please verify that the workflow is behaving as expected :)

Link to GitHub blogg:
https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Old way of working

- name: Save state
  run: echo "::save-state name={name}::{value}"
- name: Set output
  run: echo "::set-output name={name}::{value}"

New way of working

- name: Save state
  run: echo "{name}={value}" >> $GITHUB_STATE
- name: Set output
  run: echo "{name}={value}" >> $GITHUB_OUTPUT