✏️(project) fix minor typos

Found typos and fixed them.

src/backend/core/models.py

@@ -140,7 +140,7 @@ class Contact(BaseModel):
         try:
             jsonschema.validate(self.data, contact_schema)
         except jsonschema.ValidationError as e:
-            # Specify the property in the data in which the error occured
+            # Specify the property in the data in which the error occurred
             field_path = ".".join(map(str, e.path))
             error_message = f"Validation error in '{field_path:s}': {e.message}"
             raise exceptions.ValidationError({"data": [error_message]}) from e

src/backend/core/tests/test_models_oidc_user_getter.py

@@ -8,7 +8,7 @@ from core import factories, models
 pytestmark = pytest.mark.django_db
 
 
-def test_models_oidc_user_getter_exsting_user_no_email(django_assert_num_queries):
+def test_models_oidc_user_getter_existing_user_no_email(django_assert_num_queries):
     """
     When a valid token is passed, an existing user matching the token's sub should be returned.
     """