[sdk] Simplify dispose code in SelfDiagnostics

[SimonCropp]

Fixes #
Design discussion issue #

Changes

GC.SuppressFinalize is only required when a class has a finalizer. and the SuppressFinalize+Finalizer pattern is only required when u want release unmanaged resources

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• Changes in public API reviewed (if applicable)

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: SimonCropp / name: Simon Cropp (978bd8e, 065930d)
• ✅ login: CodeBlanch / name: Mikel Blanchard (8e99eeb)

[SimonCropp]

bump

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.39%. Comparing base (6e8e190) to head (8e99eeb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6072      +/-   ##
==========================================
- Coverage   86.40%   86.39%   -0.01%     
==========================================
  Files         257      257              
  Lines       11656    11650       -6     
==========================================
- Hits        10071    10065       -6     
  Misses       1585     1585              

Files with missing lines	Coverage Δ
src/OpenTelemetry/Internal/SelfDiagnostics.cs	100.00% <ø> (ø)