update schnet seaborn version (#20)

Update seaborn version to fix incompatibility with latest pandas
version. This resolves a plotting error seen in CI and Paperspace.

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Co-authored-by: Alexandre Payot <18074599+payoto@users.noreply.github.com>

Author: rahult-graphcore

graph-prediction/schnet-molecular-prediction/requirements.txt

@@ -4,6 +4,6 @@ pandas
 matplotlib
 periodictable==1.6.1
 py3Dmol==1.8.1
-seaborn==0.12.1
+seaborn
 torch-cluster==1.6.0+pt113cpu
 examples-utils[common] @ git+https://github.com/graphcore/examples-utils@latest_stable