use all, not cran

Author: lorenzwalthert

.github/workflows/benchmarking.yaml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: ubuntu-18.04,   r: '4.0.0', rspm: "https://packagemanager.rstudio.com/cran/__linux__/bionic/291"}
+          - {os: ubuntu-18.04,   r: '4.0.0', rspm: 'https://packagemanager.rstudio.com/all/__linux__/bionic/291'}
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true