fix linux

Author: lorenzwalthert

.github/workflows/end-to-end.yml

@@ -17,7 +17,7 @@ jobs:
         config:
           - {os: macOS-latest,   r: 'release'}
           - {os: windows-latest, r: 'release'}
-          - {os: ubuntu-latest,   r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/bionic/latest", http-user-agent: "R/4.0.0 (ubuntu-18.04) R (4.0.0 x86_64-pc-linux-gnu x86_64 linux-gnu) on GitHub Actions" }
+          - {os: ubuntu-latest,   r: 'release'}
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
     steps: