Test multiverse

Author: jeroen

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

@@ -17,9 +17,6 @@ jobs:
       matrix:
         config:
           - {os: macOS-latest,    r: 'release'}
-          - {os: windows-2022,    r: 'devel'}
-          - {os: windows-latest,  r: '4.1'}
-          - {os: windows-latest,  r: '3.6'}
           - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,   r: 'release'}
           - {os: ubuntu-latest,   r: 'oldrel-1'}
@@ -40,7 +37,7 @@ jobs:
         with:
           r-version: ${{ matrix.config.r }}
           http-user-agent: ${{ matrix.config.http-user-agent }}
-          use-public-rspm: true
+          extra-repositories: "https://community.r-multiverse.org"
 
       - uses: r-lib/actions/setup-r-dependencies@v2
         with: