update cache and checkout action versions, add R 3.5

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

@@ -26,7 +26,7 @@ jobs:
           - {os: ubuntu-latest,   r: 'oldrel-2'}
           - {os: ubuntu-latest,   r: 'oldrel-3'}
           - {os: ubuntu-latest,   r: 'oldrel-4'}
-          # - {os: ubuntu-latest,   r: '3.5'}
+          - {os: ubuntu-latest,   r: '3.5'}
 
     env:
       R_KEEP_PKG_SOURCE: yes
@@ -35,7 +35,7 @@ jobs:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - uses: r-lib/actions/setup-r@v2-branch
         with:
@@ -51,7 +51,7 @@ jobs:
 
       - name: Cache R packages
         if: runner.os != 'Windows'
-        uses: actions/cache@v1
+        uses: actions/cache@v3
         with:
           path: ${{ env.R_LIBS_USER }}
           key: ${{ runner.os }}-r-${{ matrix.config.r }}-1-${{ hashFiles('.github/depends.Rds') }}