Remove Summary Warnings

[dcamachoj]

When executing this action, there are a couple of warnings that appear in the Workflow Summary:

• Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/
• The set-output command is deprecated and will be disabled soon. Please upgrade to using Environment Files. For more information see: https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

The solutions are described in the provided links.
Thanks

[ApexModder]

Also running into these warnings when using this action

[hannesa2]

I see this as well

[jimschubert]

Reopening because the PR closed this automatically. The first issue should be fixed by #5.

I'll looking at the set-output issue and will close this when completed.

[jimschubert]

These issues should now be resolved.

I moved v2 to point to the new v2.1 release. I was having trouble getting GitHub releases to show the updated commit hash. GitHub's actions runner pulled the correct hash for v2, but I briefly deleted and recreated the release so everything displayed correctly in both GitHub and the actions marketplace.

Tested each version in https://github.com/jimschubert/ossify

I still need to update that project's docker/setup-buildx-action@v1, docker/login-action@v1 but all warnings are resolved for this action (see also screenshots in #5).

Shows v2 displaying the new output logging: