Update nbconvert (#680)

* update nbconvert and remove from reqs

* move nbformat to reqs since used in multiple locations

Author: zaqqwerty

requirements.txt

@@ -2,7 +2,6 @@ cirq-core>=0.13.1
 cirq-google>=0.13.1
 sympy==1.8
 numpy==1.19.5  # TensorFlow can detect if it was built against other versions.
-nbconvert==5.6.1
 nbformat==4.4.0
 pylint==2.4.4
 yapf==0.28.0
@@ -13,4 +12,4 @@ google-api-core==1.21.0
 google-auth==1.18.0
 google-api-python-client==1.8.0
 grpcio==1.34.1
-protobuf==3.17.3
+protobuf==3.17.3

scripts/ci_validate_tutorials.sh

@@ -15,7 +15,7 @@
 # ==============================================================================
 
 # Run the tutorials using the installed pip package
-pip install jupyter nbformat==4.4.0 nbconvert==5.5.0 jupyter-client==6.1.12 ipython==7.22.0
+pip install jupyter nbconvert==6.4.3 jupyter-client==6.1.12 ipython==7.22.0
 # Workaround for ipykernel - see https://github.com/ipython/ipykernel/issues/422
 pip install ipykernel==5.1.1
 # OpenAI Gym pip package needed for the quantum reinforcement learning tutorial
@@ -32,4 +32,4 @@ else
 	echo "Tutorials failed to run to completion:"
 	echo "{$examples_output}"
 	exit 64;
-fi
+fi