test: Improve OTLP Builder test

[cijothomas]

Edit: Ignore is the best option now. See #2817 (comment)

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.

Project coverage is 79.7%. Comparing base (1bce83f) to head (cbceb63).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
opentelemetry-otlp/src/exporter/mod.rs	0.0%	5 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #2817     +/-   ##
=======================================
- Coverage   80.3%   79.7%   -0.6%     
=======================================
  Files        124     124             
  Lines      23333   23341      +8     
=======================================
- Hits       18754   18624    -130     
- Misses      4579    4717    +138     

☔ 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.

[cijothomas]

This helped identify the root cause. The failures are due to some env variables being set by tests running in parallel. Given env variable are treated as high priority, this test is fragile now. The best option is to ignore them, until #2818 is resolved.

[gruebel]

👍