Apply minimum OS version enforcement to MDM SSO endpoint

[gillespi314]

Issue #22361

Checklist for submitter

If some of the following don't apply, delete the relevant line.

• Changes file added for user-visible changes in changes/, orbit/changes/ or ee/fleetd-chrome/changes.
  See Changes files for more information.
• Input data is properly validated, SELECT * is avoided, SQL injection is prevented (using placeholders for values in statements)
• Added support on fleet's osquery simulator cmd/osquery-perf for new osquery data ingestion features.
• Added/updated tests
• If paths of existing endpoints are modified without backwards compatibility, checked the frontend/CLI for any necessary changes
• If database migrations are included, checked table schema to confirm autoupdate
• For database migrations:
  • Checked schema for all modified table for columns that will auto-update timestamps during migration.
  • Confirmed that updating the timestamps is acceptable, and will not cause unwanted side effects.
  • Ensured the correct collation is explicitly set for character columns (COLLATE utf8mb4_unicode_ci).
• Manual QA for all new/changed functionality
• For Orbit and Fleet Desktop changes:
  • Orbit runs on macOS, Linux and Windows. Check if the orbit feature/bugfix should only apply to one platform (runtime.GOOS).
  • Manual QA must be performed in the three main OSs, macOS, Windows and Linux.
  • Auto-update manual QA, from released version of component to new version (see tools/tuf/test).

[codecov]

Codecov Report

Attention: Patch coverage is 45.45455% with 24 lines in your changes missing coverage. Please review.

Project coverage is 63.19%. Comparing base (8a8b840) to head (7a595d5).

Files with missing lines	Patch %	Lines
server/service/handler.go	32.25%	17 Missing and 4 partials ⚠️
cmd/fleet/serve.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #23856      +/-   ##
==========================================
- Coverage   63.20%   63.19%   -0.02%     
==========================================
  Files        1563     1563              
  Lines      148874   148917      +43     
  Branches     3700     3700              
==========================================
+ Hits        94103    94110       +7     
- Misses      47351    47371      +20     
- Partials     7420     7436      +16     

Flag	Coverage Δ
backend	64.04% <45.45%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests
• JS Bundle Analysis - Avoid shipping oversized bundles