Added concurrency to section repo creation

Author: mattpocock

.github/workflows/section-repos.yml

@@ -4,6 +4,10 @@ on:
     branches:
       - "main"
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   run:
     runs-on: ubuntu-latest