fix(conversation): Only trigger event with users that really got removed

[nickvergessen]

☑️ Resolves

• Fix Participants from a team/group, promoted to moderators, are kicked out if team/group is removed #14390

🛠️ API Checklist

42 is my moderator user that triggered the action:

Before:

No longer invited to 66vfwn2f: Array                                                                            │
│(                                                                                                                                                                            │
│    [0] => 02d68bf5-3e5c-4bac-bd45-6f1925279d29                                                                                                                              │
│    [1] => 42                                                                                                                                                                │
│    [2] => 649a454f-4ea9-4332-8c5e-4aceda302c60                                                                                                                              │
│    [3] => 846b1496-4732-4ce6-aacc-fc0a06a34429                                                                                                                              │
│    [4] => be7fb6dd 702e 4913 af5d c48718bfc8c9                                                                                                                              │
│    [5] => ce0d5740-7aaf-4332-a267-6bbfae2603c0                                                                                                                              │
│    [6] => fb03192a-639a-4735-8a58-1a3108751a94                                                                                                                              │
│)                                                       

After:

spreed-hpb   No longer invited to 66vfwn2f: Array                                                                            │
│(                                                                                                                                                                            │
│    [0] => 02d68bf5-3e5c-4bac-bd45-6f1925279d29                                                                                                                              │
│    [1] => 649a454f-4ea9-4332-8c5e-4aceda302c60                                                                                                                              │
│    [2] => 846b1496-4732-4ce6-aacc-fc0a06a34429                                                                                                                              │
│    [3] => be7fb6dd 702e 4913 af5d c48718bfc8c9                                                                                                                              │
│    [4] => ce0d5740-7aaf-4332-a267-6bbfae2603c0                                                                                                                              │
│    [5] => fb03192a-639a-4735-8a58-1a3108751a94                                                                                                                              │
│)                                                   

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not possible
• 📘 API documentation in docs/ has been updated or is not required
• 🔖 Capability is added or not needed

[nickvergessen]

/backport to stable31

[nickvergessen]

/backport to stable30

[nickvergessen]

/backport to stable29