disable testing nightly

Author: t-kalinowski

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

@@ -47,7 +47,7 @@ jobs:
           # these are allowed to fail
           # - {os: 'ubuntu-20.04', tf: 'default', r: 'devel'}
           # - {os: 'ubuntu-20.04', tf: '2.7.0rc1', r: 'release'}
-          - {os: 'ubuntu-20.04', tf: 'nightly' , r: 'release'}
+          # - {os: 'ubuntu-20.04', tf: 'nightly' , r: 'release'}
 
     runs-on: ${{ matrix.os }}
     continue-on-error: ${{ matrix.tf == 'nightly' || contains(matrix.tf, 'rc') || matrix.r == 'devel' }}