opentelemetry-opentracing-shim: add fixed setuptools version in test requirements

Use latest version < 78.0.0 because they removed support to parse the
setup.cfg (description-file) used in opentracing.

Author: xrmx

shim/opentelemetry-opentracing-shim/test-requirements.txt

@@ -11,6 +11,7 @@ tomli==2.0.1
 typing_extensions==4.10.0
 wrapt==1.16.0
 zipp==3.19.2
+setuptools==77.0.3
 -e opentelemetry-api
 -e opentelemetry-sdk
 -e tests/opentelemetry-test-utils