PAPP-28462: Update deprecated versions

[rgil-splunk]

Update deprecated GitHub features found in warnings on release workflow: https://github.com/splunk-soar-connectors/splunk/actions/runs/4732732321

• Upgrade uses of checkout v2 to checkout v3 which uses node 16: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/
• Update uses of save-output to use the new format: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/