Slot Mappings: Remove unnecessary checks in Validator.verify_slot_mappings()

[ancalita]

Context: The newly added method Validator.verify_slot_mappings had originally 2 checks that don't make sense any more (would incorrectly cause rasa data validate to fail):

1. if form_slots and slot.name not in form_slots statement should be removed because it didn't take into account the case of dynamic slots requested dynamically by forms.

2. if mapping.get("type") == str(SlotMapping.FROM_TRIGGER_INTENT) and slot.name not in all_required_slots statement should be removed since we're recommending in the docs that any slots that are filled with info from a form trigger intent should have a mapping without conditions to prevent the form from re-asking for this slot again.

Definition of Done:

• the 2 if statements listed above are removed and tests adapted/removed for these 2 cases.

[ancalita]

Item number 2 was taken care of in PR #11588.

[sync-by-unito]

➤ Maxime Verger commented:

💡 Heads up! We're moving issues to Jira: https://rasa-open-source.atlassian.net/browse/OSS.

From now on, this Jira board is the place where you can browse (without an account) and create issues (you'll need a free Jira account for that). This GitHub issue has already been migrated to Jira and will be closed on January 9th, 2023. Do not forget to subscribe to the corresponding Jira issue!

➡️ More information in the forum: https://forum.rasa.com/t/migration-of-rasa-oss-issues-to-jira/56569.