ci: fix backfill-corr-ci to R 4.2

Author: dshemetov

.github/workflows/backfill-corr-ci.yml

@@ -26,11 +26,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up R 4.3
+      - name: Set up R 4.2
         uses: r-lib/actions/setup-r@v2
         with:
           use-public-rspm: true
-          r-version: 4.3
+          r-version: 4.2
 
       - name: Get date
         id: get-date