Remove Duplicate Declaration of pandas in `Dockerfile` (#6959)

### Description

This pull request removes the redundant installation of `pandas` from
the `Dockerfile`.
It was previously declared twice, and this update eliminates the
duplicate entry, improving the clarity and maintainability of the
`Dockerfile`.


018ece5af2/docker/Dockerfile (L124)


018ece5af2/docker/Dockerfile (L135)

### Changes

Removed the duplicate pandas installation line from the `RUN pip
install` command.

docker/Dockerfile

@@ -132,7 +132,6 @@ RUN pip install psutil \
         sentencepiece \
         msgpack \
         requests \
-        pandas \
         sphinx \
         sphinx_rtd_theme \
         scipy \