TruffleRuby Test Exporter test failling

On PRs https://github.com/open-telemetry/opentelemetry-ruby/pull/1442 and https://github.com/open-telemetry/opentelemetry-ruby/pull/1474, the CI workflow's opentelemetry-exporter-otlp-http / ubuntu latest job on the Truffle Ruby step failed the following test:

  1) Failure:
OpenTelemetry::Exporter::OTLP::HTTP::TraceExporter::#export#test_0016_translates all the things [/home/runner/work/opentelemetry-ruby/opentelemetry-ruby/exporter/otlp-http/test/opentelemetry/exporter/otlp/http/trace_exporter_test.rb:634]:
The request POST http://localhost:4318/v1/traces with given block was expected to execute 1 time but it executed 0 times

The following requests were made:

POST http://localhost:4318/v1/traces with body '���d���•ͥ�%T�����ZRT�W�������*��ś_����R�CU����^���*���RT�R!���,��83?O����P�X�@h53�[IQbrj�[����������u3,��N��
�4�����o�	��@-����F��g0j�w�Pn��Ȩb�`r��W�rG����J?��V�L��bK��zƀ����*Ts�ܰ��rߔ��aH�p$�����Z~X;O�3�9g�Ӯ��krFfN�
��Vc{�x�s1&	1	0z�q1�	q*Κ	�A�BLL^\\��B�\�e�9^�\��B\Z\L�@�%���1�'��B��e@/Kqq�$��
�jei�j%�J`�2	�q�q��d��C�kp�)`{�z�<�؊S���o�d�A2sZp-�>v' with headers {'Accept'=>'*/*', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Content-Encoding'=>'gzip', 'Content-Type'=>'application/x-protobuf', 'User-Agent'=>'Ruby'} was made 1 time

Failed action

This test failure does not seem to be related to the changes in the PRs with the failed test. I'm not sure when it started, but the earliest failure I can find is on #1442 as of June 17.