typo (#2415)

Author: Borda

.github/workflows/docker-builds.yml

@@ -18,7 +18,7 @@ jobs:
         pytorch_version: [1.3, 1.4, 1.5]
         exclude:
           # excludes PT 1.3 as it is missing on pypi
-          - python-version: 3.8
+          - python_version: 3.8
             pytorch_version: 1.3
     steps:
       - name: Checkout