Add pybind11 to the mlir-nvidia Docker image to be able to enable the MLIR Python bindings

Differential Revision: https://reviews.llvm.org/D90966
diff --git a/buildbot/google/docker/buildbot-mlir-nvidia/Dockerfile b/buildbot/google/docker/buildbot-mlir-nvidia/Dockerfile
index 69ba353..0c21440 100644
--- a/buildbot/google/docker/buildbot-mlir-nvidia/Dockerfile
+++ b/buildbot/google/docker/buildbot-mlir-nvidia/Dockerfile
@@ -18,7 +18,7 @@
 RUN apt-get update; \
     apt-get install -y software-properties-common apt-transport-https ca-certificates \
       clang-8 lld-8 ninja-build git wget gnupg ccache \
-      python python-pip python-psutil ;\
+      python python-pip python-psutil pybind11-dev ;\
     update-alternatives --install /usr/bin/clang clang /usr/bin/clang-8 100 ;\
     update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-8 100 ;\
     update-alternatives --install /usr/bin/lld lld /usr/bin/lld-8 100