[Docker] use latest netron, v. spec already out of date

docker/Dockerfile.finn_dev

@@ -56,7 +56,7 @@ RUN pip install sphinx==3.1.2
 RUN pip install sphinx_rtd_theme==0.5.0
 RUN pip install pytest-xdist==2.0.0
 RUN pip install pytest-parallel==0.1.0
-RUN pip install netron==4.4.7
+RUN pip install netron
 RUN pip install -e git+https://github.com/fbcotter/dataset_loading.git@0.0.4#egg=dataset_loading
 
 # switch user