Fetch support_bot per organization

What does this MR do and why?

This code change updates how the system handles "support bot" users in a service desk feature. Previously, the system used a single global support bot for all organizations, but now it creates organization-specific support bots.

The main changes involve replacing calls to Users::Internal.support_bot with Users::Internal.for_organization(organization_id).support_bot throughout the codebase.

This is part 3/3 of MRs to change the way we fetch support bot

• The first one, removed all specs where we didn't need to define the support bot. : !205685 (merged)
• The second one, we update all the specs in order to fetch the support bot though the organization: !206532

References

#565281

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