Relax datasets version pin to avoid conflict with TRT-LLM

The tensorrt_llm 1.3.0rc5 container pins datasets==3.1.0. The previous
pin (>=4.4.0) caused concurrent pip installs across ranks to race and
corrupt the datasets package, breaking tensorrt_llm imports entirely.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Ye Yu <yeyu@nvidia.com>

Author: yeyu-nvidia

examples/specdec_bench/requirements_speed.txt

@@ -1,4 +1,4 @@
-datasets>=4.4.0,<5.0.0
+datasets>=3.1.0
 rich>=14.2.0
 seaborn>=0.13.2
 tiktoken>=0.12.0