fix: Apply DD_VERSION on all spans that use the default or global service name

[mabdinur]

What does this PR do?

Addresses a broken edge case introduced by: #4027.

Edge Case: When a global service name and a global version are set (for example via DD_SERVICE and DD_VERSION) and a span is initialized without a service name, the global version MUST be set on the span. As of v2.5.0 this is no longer the case.

Motivation:

This bug was detected when v2.5.0 was released and the following system failed: Test_Config_UnifiedServiceTagging::test_specific_version.

Change log entry

Fix

• Tracing: Ensure the global version tag is set on spans that have the global service name.

Additional Notes:

How to test the change?

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.73%. Comparing base (dedb0bb) to head (f909bd2).
Report is 169 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4075      +/-   ##
==========================================
+ Coverage   97.72%   97.73%   +0.01%     
==========================================
  Files        1338     1338              
  Lines       80248    80265      +17     
  Branches     4016     4016              
==========================================
+ Hits        78420    78448      +28     
+ Misses       1828     1817      -11     

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

---

🚨 Try these New Features:

• Flaky Tests Detection - Detect and resolve failed and flaky tests
• JS Bundle Analysis - Avoid shipping oversized bundles

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-11-05 21:26:15

Comparing candidate commit f909bd2 in PR branch munir/fix-version-tagging with baseline commit dedb0bb in branch master.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 28 metrics, 2 unstable metrics.

scenario:tracing - Propagation - Datadog

• 🟥 throughput [-2516.167op/s; -2418.738op/s] or [-7.662%; -7.366%]