[PM-17593] Remove Multi-Org Enterprise feature flag

[jonashendrickx]

🎟️ Tracking

https://bitwarden.atlassian.net/browse/PM-17593

📔 Objective

Remove the feature flag for multi-organization enterprises.

📸 Screenshots

⏰ Reminders before review

• Contributor guidelines followed
• All formatters and local linters executed and passed
• Written new unit and / or integration tests where applicable
• Protected functional changes with optionality (feature flags)
• Used internationalization (i18n) for all UI strings
• CI builds passed
• Communicated to DevOps any deployment requirements
• Updated any necessary documentation (Confluence, contributing docs) or informed the documentation team

🦮 Reviewer guidelines

• 👍 (:+1:) or similar for great changes
• 📝 (:memo:) or ℹ️ (:information_source:) for notes or general info
• ❓ (:question:) for questions
• 🤔 (:thinking:) or 💭 (:thought_balloon:) for more open inquiry that's not quite a confirmed issue and could potentially benefit from discussion
• 🎨 (:art:) for suggestions / improvements
• ❌ (:x:) or ⚠️ (:warning:) for more significant problems or concerns needing attention
• 🌱 (:seedling:) or ♻️ (:recycle:) for future improvements or indications of technical debt
• ⛏ (:pick:) for minor or nitpick changes

[github-actions]

LaunchDarkly flag references

❌ 1 flag removed

Name	Key	Aliases found	Info
Provider portal for multi-organization enterprises	pm-12275-multi-organization-enterprises		✅ all references removed

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 44.22%. Comparing base (443a147) to head (6441d3e).
Report is 43 commits behind head on main.

Files with missing lines	Patch %	Lines
src/Admin/AdminConsole/Views/Providers/Edit.cshtml	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5351      +/-   ##
==========================================
- Coverage   44.31%   44.22%   -0.09%     
==========================================
  Files        1483     1487       +4     
  Lines       68440    68580     +140     
  Branches     6174     6176       +2     
==========================================
+ Hits        30326    30332       +6     
- Misses      36805    36939     +134     
  Partials     1309     1309              

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[github-actions]

Checkmarx One – Scan Summary & Details – b61fd806-74e1-4403-853b-1cb1d213f34c

Fixed Issues (3)

Great job! The following issues were fixed in this Pull Request

Severity	Issue	Source File / Package
	Heap_Inspection	/src/Core/AdminConsole/Services/Implementations/RabbitMqEventWriteService.cs: 19
	Heap_Inspection	/src/Core/AdminConsole/Services/Implementations/RabbitMqEventListenerBase.cs: 29
	Heap_Inspection	/src/Core/Settings/GlobalSettings.cs: 268