Pin pytorch-lightning & torchmetrics. (#1073)

Latest versions causing the following error at runtime:

```
...
  File "/opt/conda/lib/python3.7/site-packages/torchmetrics/utilities/imports.py", line 33, in _module_available
    return find_spec(module_path) is not None
  File "/opt/conda/lib/python3.7/importlib/util.py", line 114, in find_spec
    raise ValueError('{}.__spec__ is None'.format(name))
ValueError: transformers.__spec__ is None
```

Also, remove /opt/conda/lib from LD_LIBRARY_PATH only when fetching
packages over https using apt.

Otherwise, this is causing an issue with scipy which expects a different
version of glibc.

http://b/198635596

Author: rosbo

Dockerfile

@@ -25,7 +25,7 @@ RUN sed -i "s/httpredir.debian.org/debian.uchicago.edu/" /etc/apt/sources.list &
     /tmp/clean-layer.sh
 
 # Make sure the dynamic linker finds the right libstdc++
-ENV LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu:/opt/conda/lib
+ENV LD_LIBRARY_PATH=/opt/conda/lib
 # b/128333086: Set PROJ_LIB to points to the proj4 cartographic library.
 ENV PROJ_LIB=/opt/conda/share/proj
 
@@ -391,7 +391,9 @@ RUN pip install flashtext && \
     pip install tensorflow-datasets && \
     pip install pydub && \
     pip install pydegensac && \
-    pip install pytorch-lightning && \
+    # b/198635596 latest versions of torchmetrics & pytorch-lightning are failing at runtime.
+    pip install torchmetrics==0.5.0 && \
+    pip install pytorch-lightning==1.4.4 && \
     pip install datatable && \
     pip install sympy && \
     # flask is used by agents in the simulation competitions.

gpu.Dockerfile

@@ -21,11 +21,8 @@ ENV PATH=/usr/local/nvidia/bin:/usr/local/cuda/bin:/opt/bin:${PATH}
 # CUDA user libraries, either manually or through the use of nvidia-docker) exclude them. One
 # convenient way to do so is to obscure its contents by a bind mount:
 #   docker run .... -v /non-existing-directory:/usr/local/cuda/lib64/stubs:ro ...
-ENV LD_LIBRARY_PATH_NO_STUBS="/usr/local/nvidia/lib64:/usr/local/cuda/lib64:$LD_LIBRARY_PATH"
-ENV LD_LIBRARY_PATH="/usr/local/nvidia/lib64:/usr/local/cuda/lib64:/usr/local/cuda/lib64/stubs:$LD_LIBRARY_PATH"
-ENV NVIDIA_VISIBLE_DEVICES=all
-ENV NVIDIA_DRIVER_CAPABILITIES=compute,utility
-ENV NVIDIA_REQUIRE_CUDA="cuda>=$CUDA_MAJOR_VERSION.$CUDA_MINOR_VERSION"
+# b/197989446#comment7 libgnutls version at /opt/conda/lib causes apt to fail to fetch packages using https URLs.
+ENV LD_LIBRARY_PATH=/usr/lib/x86_64-linux-gnu
 RUN apt-get update && apt-get install -y --no-install-recommends \
       cuda-cupti-$CUDA_VERSION \
       cuda-cudart-$CUDA_VERSION \
@@ -43,6 +40,12 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     ln -s /usr/local/cuda/lib64/stubs/libcuda.so /usr/local/cuda/lib64/stubs/libcuda.so.1 && \
     /tmp/clean-layer.sh
 
+ENV LD_LIBRARY_PATH_NO_STUBS="/usr/local/nvidia/lib64:/usr/local/cuda/lib64:/opt/conda/lib"
+ENV LD_LIBRARY_PATH="/usr/local/nvidia/lib64:/usr/local/cuda/lib64:/usr/local/cuda/lib64/stubs:/opt/conda/lib"
+ENV NVIDIA_VISIBLE_DEVICES=all
+ENV NVIDIA_DRIVER_CAPABILITIES=compute,utility
+ENV NVIDIA_REQUIRE_CUDA="cuda>=$CUDA_MAJOR_VERSION.$CUDA_MINOR_VERSION"
+
 # Install OpenCL & libboost (required by LightGBM GPU version)
 RUN apt-get install -y ocl-icd-libopencl1 clinfo libboost-all-dev && \
     mkdir -p /etc/OpenCL/vendors && \