Fix Deprecating save-state and set-output commands

[ktasper]

As per Github's Annocument this repo should be updated to use:

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

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

Instead of the derepecating:

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

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

I have a PR for this here

[EnricoMi]

Merged, thanks for raising this.