docker-tests: bump requests to 2.31.0 (#4476)

So that opentelemetry-test-utils is happy but the custom docker schema
continue to work.

Author: xrmx

tests/opentelemetry-docker-tests/tests/test-requirements.txt

@@ -58,7 +58,7 @@ python-dotenv==0.21.1
 pytz==2024.1
 PyYAML==5.3.1
 redis==5.0.1
-requests==2.25.0
+requests==2.31.0
 six==1.16.0
 SQLAlchemy==1.4.52
 texttable==1.7.0