Merge #3467

3467: Identify builds git tagged with `prototype-...` in CLI and analytics r=curquiza a=dureuill

# Pull Request

## What does this PR do?

- Parses the last git tag to extract a prototype name if:
  - Current build uses the prototype tag (not after the tag) precisely
  - The prototype tag name respects the following conditions:
    1. starts with `prototype-`
    2. ends with a number
    3. the hyphen-separated segment right before the number is not a number (required to reject commits after the tag).
- Display the prototype name in the launch summary in the CLI
- Send the prototype name to analytics if any
- Update prototypes instructions in CONTRIBUTING.md

|`VERGEN_GIT_SEMVER_LIGHTWEIGHT` value | Prototype |
|---|---|
| `Some("prototype-geo-bounding-box-0-139-gcde89018")` | `None` (does not end with a number) |
| `Some("prototype-geo-bounding-box-0-139-89018")` | `None` (before the last segment is a number) |
| `Some("prototype-geo-bounding-box-0")` | `Some("prototype-geo-bounding-box-0")` |
| `Some("prototype-geo-bounding-box")` | `None` (does not end with a number") |
| `Some("geo-bounding-box-0")` | `None` (does not start with "prototype") |
| `None` | `None` | 

Co-authored-by: Louis Dureuil <louis@meilisearch.com>

.github/workflows/publish-docker-images.yml

@@ -92,6 +92,7 @@ jobs:
           build-args: |
             COMMIT_SHA=${{ github.sha }}
             COMMIT_DATE=${{ steps.build-metadata.outputs.date }}
+            GIT_TAG=${{ github.ref_name }}
 
       # /!\ Don't touch this without checking with Cloud team
       - name: Send CI information to Cloud team