updating ubuntu version for guithub actions

Author: Schuch666

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

@@ -24,12 +24,12 @@ jobs:
         config:
           - { os: windows-latest, r: "release" }
           - {
-              os: ubuntu-20.04,
+              os: ubuntu-24.04,
               r: "release",
               rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest",
             }
           - {
-              os: ubuntu-20.04,
+              os: ubuntu-24.04,
               r: "devel",
               rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest",
             }