Update check workflow

Author: kenkellner

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

@@ -24,7 +24,7 @@ jobs:
         config:
           #- {os: windows-latest, r: 'release'}
           #- {os: macOS-latest, r: 'release'}
-          - {os: ubuntu-20.04, r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
+          - {os: ubuntu-24.04, r: 'release'}
             #- {os: ubuntu-20.04, r: 'devel', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
 
     env: