[gha] Create release.yml and changelog.yml file

[jjmerchante]

This PR adds a new GitHub Action to create the release for ELK. It generates a package, tests it, and publishes the release on PyPi and GitHub whenever a tag is generated and pushed.

This PR also includes a workflow to check if the changelog for the releases is included

It also updates statsmodels package in Poetry to 0.12.0 because 0.9.0 after a poetry build doesn't install the dependency numpy and fails.

This PR depends on https://github.com/chaoss/grimoirelab-github-actions/pull/1

[coveralls]

Pull Request Test Coverage Report for Build 2095527409

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.02%) to 81.956%

---

Files with Coverage Reduction	New Missed Lines	%
/home/runner/work/grimoirelab-elk/grimoirelab-elk/grimoire_elk/enriched/github.py	2	75.31%
<!--	Total:	2		-->

Totals
Change from base Build 2027488998:	-0.02%
Covered Lines:	8775
Relevant Lines:	10707

---

💛 - Coveralls

[vchrombie]

@jjmerchante we just have this PR left in the task list. It would be great if you can update the PR when you get some free time. Thank you.

[vchrombie]

Thanks for the PR @jjmerchante.