chore(actions): use newer method to set an output parameter

[gustavovalverde]

Motivation

The set-output command is deprecated and will be disabled soon.
For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

Fixes #5736

Specifications

• https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-output-parameter

Solution

Apply the method used in the specifications.

Review

Anyone can review this

Reviewer Checklist

• Will the PR name make sense to users?
  • Does it need extra CHANGELOG info? (new features, breaking changes, large changes)
• Are the PR labels correct?
• Does the code do what the ticket and PR says?
  • Does it change concurrent code, unsafe code, or consensus rules?
• How do you know it works? Does it have tests?

[teor2345]

I'm still seeing some set-output warnings, maybe they are from actions we are using? Do we need a separate ticket to upgrade those actions before May?
https://github.com/ZcashFoundation/zebra/actions/runs/4020943497
https://github.com/ZcashFoundation/zebra/actions/runs/4020943505

There were also some errors in release drafter, but they seem to be unrelated to these changes.

[gustavovalverde]

@teor2345 I just fixed the replacements I made by mistake.

About the remaining errors, I created a ticket for that:

• ci: migrate actions using the unmaintained actions-rs/* repository #6048

[teor2345]

Thanks, that looks great!