Try using r-lib/actions#879 for 3.6 support (#363)

Author: DavisVaughan

.github/workflows/R-CMD-check.yaml

@@ -50,7 +50,8 @@ jobs:
 
       - uses: r-lib/actions/setup-pandoc@v2
 
-      - uses: r-lib/actions/setup-r@v2
+      # TODO: Go back to `@v2` when https://github.com/r-lib/actions/pull/879 is merged
+      - uses: r-lib/actions/setup-r@e01532e2602ddc137f42ed6d1e3aeee289b7d2dc
         with:
           r-version: ${{ matrix.config.r }}
           http-user-agent: ${{ matrix.config.http-user-agent }}