[RELEASE] Prepare release 1.9.1

[marcalff]

Fixes #2148

Changes

Please provide a brief description of the changes here.

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

Merging #2149 (bbb4f48) into main (32a8235) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2149   +/-   ##
=======================================
  Coverage   87.17%   87.17%           
=======================================
  Files         166      166           
  Lines        4777     4777           
=======================================
  Hits         4164     4164           
  Misses        613      613           

[marcalff]

@owent

Do we also need update version.h?

Both files:

./api/include/opentelemetry/version.h
./sdk/include/opentelemetry/sdk/version/version.h

are updated.

[esigo]

LGTM
Thanks :)

[owent]

@owent

Do we also need update version.h?

Both files:

./api/include/opentelemetry/version.h ./sdk/include/opentelemetry/sdk/version/version.h

are updated.

Thanks, maybe there is some wrong with my network, I find only one changed file when first open this PR, and there is no problem now.

[marcalff]

Release on hold, waiting for:

• [BUILD] Transitive dependency issue with the otlp http exporter #2153
• [BUILD] Transitive dependency issue with the otlp http exporter #2154

to avoid breaking the build for applications with 1.9.1