Improve the bot message disabling with multiple policies

What does this MR do and why?

Improve the bot message disabling with multiple policies

Check if the bot message can be disabled by cross-referencing the violated policies. Non-violated policies shouldn't contribute to the decision whether the bot comment can be skipped.

This allows to reduce noise from the bot comment for any_merge_request policies with send_bot_message: false but keep the bot message active for other policies, such as for critical vulnerabilities.

References

Screenshots or screen recordings

Before	After
CleanShot_2025-06-12_at_07.29.50	CleanShot_2025-06-12_at_07.27.42

How to set up and validate locally

1. Create a project
2. Create two policies:

   approval_policy:
   - name: Critical
     description: ''
     enabled: true
     rules:
     - type: scan_finding
       scanners: []
       vulnerabilities_allowed: 0
       severity_levels:
       - critical
       vulnerability_states: []
       branch_type: protected
     actions:
     - type: require_approval
       approvals_required: 1
       role_approvers:
       - maintainer
       - owner
     - type: send_bot_message
       enabled: true
     approval_settings:
       block_branch_modification: false
       prevent_pushing_and_force_pushing: false
       prevent_approval_by_author: false
       prevent_approval_by_commit_author: false
       remove_approvals_with_new_commit: false
       require_password_to_approve: false
     fallback_behavior:
       fail: closed
   - name: Protected branch approval
     description: ''
     enabled: true
     rules:
     - type: any_merge_request
       branch_type: protected
       commits: any
     actions:
     - type: require_approval
       approvals_required: 1
       role_approvers:
       - owner
       - maintainer
     - type: send_bot_message
       enabled: false
     approval_settings:
       block_branch_modification: false
       prevent_pushing_and_force_pushing: false
       prevent_approval_by_author: false
       prevent_approval_by_commit_author: false
       remove_approvals_with_new_commit: false
       require_password_to_approve: false
     fallback_behavior:
       fail: closed
   

3. Create a MR
4. Verify that bot message is not posted for the any_merge_request policy
5. Update the MR by adding a new critical finding violation
6. Verify that bot message is posted for the critical finding violation

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #549026 (closed)