Switch action's code to run on Node 16

[michalinacienciala]

GH is deprecating usage of node12 in custom GH Actions. Using an action which runs on node12 throws a warning:

The following actions uses node12 which is deprecated and will be forced to run on node16: tretuna/[email protected]. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/