Remove test runner concurrency (#1482)

Author: sebasslash

.github/workflows/ci.yml

@@ -19,13 +19,13 @@ jobs:
   tests:
     name: run
     runs-on: ubuntu-latest
-    timeout-minutes: 40
+    timeout-minutes: 60
     strategy:
       fail-fast: false
       matrix:
         # If you adjust these parameters, also adjust the jrm input files on the "Merge reports" step below
-        total: [ 5 ]
-        index: [ 0, 1, 2, 3, 4 ]
+        total: [ 1 ]
+        index: [ 0 ]
     steps:
       - name: Fetch Outputs
         id: tflocal