🗃️(teams) remove slug field

After some reflexion, the use of a slug field raises to many
problems without being really needed.

One problem is the slug is made from the group name, but we
don't have unicity on this, so a user might be blocked without
any clue.

We also want to allow group names to be reused (which is already
allowed except for the automatic slug).

The unique ID that will be shared with Service Providers will be
the PK/UUID.

src/backend/core/models.py

@@ -22,7 +22,6 @@ from django.db import models, transaction
 from django.template.loader import render_to_string
 from django.utils import timezone
 from django.utils.functional import lazy
-from django.utils.text import slugify
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import override
 
@@ -486,7 +485,6 @@ class Team(BaseModel):
     """
 
     name = models.CharField(max_length=100)
-    slug = models.SlugField(max_length=100, unique=True, null=False, editable=False)
 
     users = models.ManyToManyField(
         User,
@@ -511,15 +509,6 @@ class Team(BaseModel):
     def __str__(self):
         return self.name
 
-    def save(self, *args, **kwargs):
-        """Override save function to compute the slug."""
-        self.slug = self.get_slug()
-        return super().save(*args, **kwargs)
-
-    def get_slug(self):
-        """Compute slug value from name."""
-        return slugify(self.name)
-
     def get_abilities(self, user):
         """
         Compute and return abilities for a given user on the team.