Reinstate downstream tests

Author: ianthomas23

.github/workflows/downstream.yml

@@ -90,7 +90,6 @@ jobs:
 
   qtconsole:
     runs-on: ubuntu-latest
-    if: false
     timeout-minutes: 20
     steps:
       - name: Checkout
@@ -123,7 +122,6 @@ jobs:
 
   spyder_kernels:
     runs-on: ubuntu-latest
-    if: false
     timeout-minutes: 20
     steps:
       - name: Checkout