Install specific version of boto3, because 1.26.103 is broken (#1237)

http://b/276344496

Author: Philmod

Dockerfile.tmpl

@@ -55,6 +55,10 @@ ADD clean-layer.sh  /tmp/clean-layer.sh
 ADD patches/nbconvert-extensions.tpl /opt/kaggle/nbconvert-extensions.tpl
 ADD patches/template_conf.json /opt/kaggle/conf.json
 
+# b/276344496: Install specific version of boto3, because 1.26.103 is broken.
+RUN pip install boto3==1.26.100 && \
+    /tmp/clean-layer.sh
+
 {{ if eq .Accelerator "gpu" }}
 # b/200968891 Keeps horovod once torch is upgraded.
 RUN pip uninstall -y horovod && \