Revert "Update test_and_build.yml to not run the other sites"

This reverts commit 24210cd.

Author: cdkharris

.github/workflows/test_and_build.yml

@@ -60,6 +60,13 @@ jobs:
     strategy:
       matrix:
         HPC_JEKYLL_CONFIG:
+          - Birmingham_Baskerville_slurm
+          - ComputeCanada_Graham_slurm
+          - EPCC_Cirrus_slurm
+          - HPCC_MagicCastle_slurm
+          - Magic_Castle_EESSI_slurm
+          - NIST_CTCMS_slurm
+          - Norway_SIGMA2_SAGA_slurm
           - UCL_Myriad_sge
     steps:
       - uses: actions/checkout@v2