[Build/CI] Add tracing deps to vllm container image

A report requested that these dependencies be included in the image
for tracing. That seems reasonable - they are needed by
`vllm.tracing`. Stop manually installing them in the relevant test
pipeline and just include them in the image.

Signed-off-by: Russell Bryant <[email protected]>

Author: russellb

.buildkite/test-pipeline.yaml

@@ -163,11 +163,6 @@ steps:
   - tests/tracing
   commands:
   - pytest -v -s metrics
-  - "pip install \
-      'opentelemetry-sdk>=1.26.0,<1.27.0' \
-      'opentelemetry-api>=1.26.0,<1.27.0' \
-      'opentelemetry-exporter-otlp>=1.26.0,<1.27.0' \
-      'opentelemetry-semantic-conventions-ai>=0.4.1,<0.5.0'"
   - pytest -v -s tracing
 
 ##### fast check tests  #####

requirements/common.txt

@@ -43,3 +43,7 @@ watchfiles # required for http server to monitor the updates of TLS files
 python-json-logger # Used by logging as per examples/other/logging_configuration.md
 scipy # Required for phi-4-multimodal-instruct
 ninja # Required for xgrammar, rocm, tpu, xpu
+opentelemetry-sdk>=1.26.0,<1.27.0  # vllm.tracing
+opentelemetry-api>=1.26.0,<1.27.0  # vllm.tracing
+opentelemetry-exporter-otlp>=1.26.0,<1.27.0  # vllm.tracing
+opentelemetry-semantic-conventions-ai>=0.4.1,<0.5.0  # vllm.tracing