[SEMANTIC CONVENTIONS] Upgrade to version 1.26.0

[marcalff]

Fixes # (issue)

Changes

Please provide a brief description of the changes here.

• Upgraded to semantic conventions release v1.26.0
• Implemented a workaround for a C++ name collision:
  • deprecated semconv messaging.client_id is generated as kMessagingClientId
  • semconv messaging.client.id is generated as kMessagingClientId
  • removed code generation for messaging.client_id

See related:

• messaging.client_id -> messaging.client.id rename causes issues with code generation semantic-conventions#1031

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.68%. Comparing base (497eaf4) to head (1ac80cc).
Report is 71 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2687      +/-   ##
==========================================
+ Coverage   87.12%   87.68%   +0.56%     
==========================================
  Files         200      190      -10     
  Lines        6109     5849     -260     
==========================================
- Hits         5322     5128     -194     
+ Misses        787      721      -66     

see 58 files with indirect coverage changes

[lalitb]

btw used similar workaround for otel-rust - open-telemetry/opentelemetry-rust#1851 :)