ci: Use `dart pub publish` command for release workflows

[Nidal-Bakir]

New Pull Request Checklist

• [x] I am not disclosing a vulnerability.
• [x] I am creating this PR in reference to an issue.

Issue Description

Closes: #881

Approach

Using the recommended solution by the Flutter team publishing packages using GitHub actions

TODOs before merging

@mtrezza There are some steps you need to do in the pub.dev admin tab to enable this.

On the Dart SDK admin tab add the following

On the Flutter SDK admin tab add the following

Make sure to follow this hardening security with tag-protection rules on github

• [ ] Add tests
• [ ] Add changes to documentation (guides, repository pages, in-code descriptions)
• [ ] A changelog entry

[parse-github-assistant[bot]]

Thanks for opening this pull request!

• 🎉 We are excited about your hands-on contribution!

[codecov[bot]]

Codecov Report

Patch and project coverage have no change.

Comparison is base (74f45b9) 38.68% compared to head (2da9e7d) 38.68%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #886 +/- ## ======================================= Coverage 38.68% 38.68% ======================================= Files 56 56 Lines 3278 3278 ======================================= Hits 1268 1268 Misses 2010 2010 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.

[mtrezza]

Looks good; could you also modify the manual release workflow? We need to trigger the manual release for the unpublished flutter package.

[Nidal-Bakir]

Remember to enable the automated publishing in pub.dev admin tab for each package

[Nidal-Bakir]

Yes, it is ready

[mtrezza]

It may be that the manual publish workflow doesn't work anymore, the docs say:

Only GitHub Actions triggered by a push of a tag that matches this tag pattern will be allowed to publish your package.

In that case we'd have to delete and re-push a tag to re-trigger a release. We'll see.

[mtrezza]

The workflow failed, see https://github.com/parse-community/Parse-SDK-Flutter/issues/881#issuecomment-1548752838