Update R-CMD-check.yaml

Author: jokergoo

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

@@ -25,7 +25,6 @@ jobs:
           - {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-20.04,   r: 'devel', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest", http-user-agent: "R/4.1.0 (ubuntu-20.04) R (4.1.0 x86_64-pc-linux-gnu x86_64 linux-gnu) on GitHub Actions" }
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true