Prepare for "v0.1.13 Snowflake release ❄️"

[gmaze]

Setup

• [x] Create a new branch for this release: git checkout -b prepare-v0.1.13
• [x] Increase release version in ./setup.py
• [x] Update release version in ./docs/whats-new.rst
• [x] Create a PR to prepare it, name it with one of the Nature emoji and make sure it was never used before

Prepare code for release

Code clean-up

• [x] Run codespell from repo root and fix errors: codespell -q 2
• [x] Run flake8 from repo root and fix errors

Software distribution readiness

• [x] Manually trigger upstream CI tests for the release branch and ensure they are passed
• [x] Update pinned dependencies versions in ./ci/requirements/py*-*-pinned.yml environment files using upstream CI tests information
• [x] If CI tests with the oldest dependencies versions are not passed, upgrade these versions in ./ci/requirements/py*-*-min.yml files up to the point where CI tests are passed
• [x] Possibly update ./requirements.txt and ./docs/requirements.txt if the oldest dependencies versions were upgraded in the previous step
• [x] Make sure that all CI tests are passed
• [x] Activate and make sure the documentation for the release branch is built on RTD

Preparation conclusion

• [x] Merge this PR to master
• [x] Update release date in ./docs/whats-new.rst
• [x] Make sure all CI tests are passed and RTD doc is built on the master branch

Publish the release

• [x] On the master branch, commit the release in git: git commit -a -m 'Release v0.X.Y'
• [x] Tag the release: git tag -a v0.X.Y -m 'v0.X.Y'
• [x] Push it online: git push origin v0.X.Y
• [x] Issue the release on GitHub by first "Drafting a new release" Choose the release tag v0.X.Y, fill in the release title and click on the Auto-generate release notes button.
  This will trigger the publish Github action that will push the release on Pypi.

CI tests / RTD build results

[gmaze]

There is the issue that the mocked FTP is not working under minimal versions environments, although tests succeed with an XFAIL mark

[gmaze]

Warning

This PR suffers from unexpected delays because of issues with CI tests implementation in GA

These issues lead to un-necessary long CI tests workflows, which is interfering with a standard release process (I simply can't validated every thing following my checklist).

I have the impression that the core issue is for GA jobs to efficiently connect repeatedly to remote servers: this is way too long (the test suite takes 15mins on a regular desktop at Ifremer while it requires more than 45mins on GA !). And this is not only related to the known issue of the poor performances of the Mac OS implementation on GA.

Therefore, I think I will proceed to the release without a formal checkup of the test suite, mostly because all new features have been thoroughly validated in PRs and on the master branch, and a new release is necessary asap.