Fix Prometheus target name

[lalitb]

Fixes #1819

Changes

Revert back the target name for Prometheus in otel-cpp cmake config.

This is incorrect in the latest release, probably we have to plan next release bit sooner, let's discuss in community meeting.

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

[owent]

LGTM

[codecov]

Codecov Report

Merging #1820 (a4c018e) into main (308ec88) will increase coverage by 0.06%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1820      +/-   ##
==========================================
+ Coverage   85.71%   85.77%   +0.06%     
==========================================
  Files         171      171              
  Lines        5240     5240              
==========================================
+ Hits         4491     4494       +3     
+ Misses        749      746       -3     

Impacted Files	Coverage Δ
...include/opentelemetry/sdk/common/circular_buffer.h	98.00% <0.00%> (-2.00%)	⬇️
sdk/src/trace/batch_span_processor.cc	91.41% <0.00%> (+0.79%)	⬆️
ext/src/http/client/curl/http_client_curl.cc	81.44% <0.00%> (+1.14%)	⬆️

[ThomsonTan]

What's the impact of incorrect target name? And wondering should we delay pushing 1.8.0 to package managers?

[lalitb]

What's the impact of incorrect target name? And wondering should we delay pushing 1.8.0 to package managers?

For vcpkg, it should be fine to push it with WITH_PROMETHEUS=OFF, and can be enabled in next release. There is no breaking change for vcpkg as we never pushed metrics in that.

[ThomsonTan]

What's the impact of incorrect target name? And wondering should we delay pushing 1.8.0 to package managers?

For vcpkg, it should be fine to push it with WITH_PROMETHEUS=OFF, and can be enabled in next release. There is no breaking change for vcpkg as we never pushed metrics in that, so it sounds like a breaking change there.

We cannot just set WITH_PROMETHEUS=OFF in vcpkg as we produce a sub-package with prometheus like below the user can install.

opentelemetry-cpp[prometheus] Whether to include the Prometheus Client in the SDK

[lalitb]

We cannot just set WITH_PROMETHEUS=OFF in vcpkg as we produce a sub-package with prometheus like below the user can install.

This is old Prometheus sub-package, which is has different target name ( with deprecated keyword) ?
Can we disable this package generation for v1..8.0, and enable for new Prometheus in v1.9.0 ?