Update CHANGELOG

[utpilla]

Changes

• Update CHANGELOG for the recent public API changes

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

Attention: Patch coverage is 97.81022% with 3 lines in your changes missing coverage. Please review.

Project coverage is 78.3%. Comparing base (7ab5e0f) to head (9f7b5fe).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
opentelemetry-sdk/src/metrics/internal/mod.rs	93.7%	2 Missing ⚠️
...pentelemetry-sdk/src/metrics/internal/histogram.rs	98.4%	1 Missing ⚠️

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #2124   +/-   ##
=====================================
  Coverage   78.3%   78.3%           
=====================================
  Files        121     121           
  Lines      20815   20753   -62     
=====================================
- Hits       16308   16265   -43     
+ Misses      4507    4488   -19     

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