[CI] Add action to trigger conda packages "nightly" builds

[olivier-roussel]

Similarly to what is done with regression, we wand to build conda packages of SOFA master at each commit. This action triggers workflows on conda-ci repository ( https://github.com/sofa-framework/conda-ci/blob/master/.github/workflows/devel-sofa.yml and https://github.com/sofa-framework/conda-ci/blob/master/.github/workflows/devel-sofa-python3.yml ), which will build conda "devel" packages of SOFA given at given commit (last pushed commit on master). Until now these packages were build nightly. These packages are therefore not "nightly" builds anymore, and have been renamed to "devel".
Main purpose is to have fresh SOFA binaries for the CI of plugins on multi-platform.

Packages would be hosted on the Conda channel https://prefix.dev/channels/sofa-framework-devel (hosted by Prefix.dev).

We would still have to define if we want to keep previous devel package once a new one is build, and if yes, how many / for how long ?

---

By submitting this pull request, I acknowledge that
I have read, understand, and agree SOFA Developer Certificate of Origin (DCO).

---

Reviewers will merge this pull-request only if

• it builds with SUCCESS for all platforms on the CI.
• it does not generate new warnings.
• it does not generate new unit test failures.
• it does not generate new scene test failures.
• it does not break API compatibility.
• it is more than 1 week old (or has fast-merge label).