Fix missing pyro install in deploy_on_release.

Summary: See title. It was missing in D35115132 (c1a66c6), and is blocking the 0.6.3 release.

Reviewed By: eytan

Differential Revision: D35175031

fbshipit-source-id: 51010d5a0a778e771bf40d6921eae14f38e80f46

.github/workflows/deploy_on_release.yml

@@ -86,6 +86,7 @@ jobs:
         conda install -y scipy sphinx pytest flake8
         conda install -y -c gpytorch gpytorch
         conda install -y conda-build anaconda-client
+        conda install -y -c conda-forge pyro-ppl==1.8.0
         conda config --set anaconda_upload no
     - name: Build and verify conda package
       shell: bash -l {0}