impl(v3): update opentelemetry quickstart

[scotthart]

Update opentelemetry quickstart now that it's a required dependency.

---

This change is 

[gemini-code-assist]

Summary of Changes

Hello @scotthart, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request streamlines the OpenTelemetry quickstart by updating its build configuration and documentation. It removes outdated OpenTelemetry-specific Bazel flags and revises the README.md to accurately guide users on managing OpenTelemetry's STL type implementations and CMake compilation flags for seamless integration with google-cloud-cpp, reflecting OpenTelemetry's status as a required dependency.

Highlights

• Bazel Configuration Update: Removed specific OpenTelemetry build flags (--@google_cloud_cpp//:enable_opentelemetry and --@io_opentelemetry_cpp//api:with_abseil) from the .bazelrc file, simplifying the build configuration.
• Documentation for OpenTelemetry Compatibility: Updated the README.md to reflect current best practices for OpenTelemetry compatibility, specifically addressing how OpenTelemetry handles Standard Template Library (STL) types and its interaction with Abseil.
• CMake Flag Clarification: Clarified the use of CMAKE_CXX_STANDARD and introduced the -DWITH_STL=17 flag in the README.md for compiling opentelemetry-cpp to ensure proper compatibility with google-cloud-cpp's C++17 requirement.

Changelog

• google/cloud/opentelemetry/quickstart/.bazelrc
  • Removed several blank lines.
  • Removed the build --@google_cloud_cpp//:enable_opentelemetry flag.
  • Removed commented-out instructions for build --@io_opentelemetry_cpp//api:with_abseil.
• google/cloud/opentelemetry/quickstart/README.md
  • Updated the "Compatibility with Abseil" section title to "Standard Template Library (STL) types".
  • Revised the explanation of OpenTelemetry's STL type implementations and the requirement for google-cloud-cpp to use the STL implementation.
  • Changed the recommended CMake flag from -DWITH_ABSEIL=ON to -DWITH_STL=17.
  • Updated the C++ standard requirement for google-cloud-cpp from C++14 to C++17 and clarified matching CMAKE_CXX_STANDARD with DWITH_STL.

Activity

• No human activity has been recorded on this pull request yet.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request updates the OpenTelemetry quickstart to reflect its new status as a required dependency, removing obsolete Bazel flags and updating the README with CMake build instructions, including a switch to C++17. A security review found no vulnerabilities in the changes. However, a minor inconsistency was noted in the recommended CMake flags for opentelemetry-cpp that should be addressed for clarity.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.62%. Comparing base (fba4b34) to head (9c8aacd).
⚠️ Report is 3 commits behind head on prepare-for-v3.0.0.

Additional details and impacted files

@@                  Coverage Diff                   @@
##           prepare-for-v3.0.0   #15955      +/-   ##
======================================================
+ Coverage               92.61%   92.62%   +0.01%     
======================================================
  Files                    2332     2332              
  Lines                  213322   213322              
======================================================
+ Hits                   197564   197587      +23     
+ Misses                  15758    15735      -23     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.