Typo

Author: andrjohns

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

@@ -23,8 +23,8 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: macOS-latest, r: 'devel', rtools: 'true', opencl: true}
-          - {os: macOS-latest, r: 'release', rtools: 'true', opencl: true}
+          - {os: macOS-latest, r: 'devel', rtools: '', opencl: true}
+          - {os: macOS-latest, r: 'release', rtools: '', opencl: true}
           - {os: windows-latest, r: 'devel', rtools: '44'}
           - {os: windows-latest, r: 'release', rtools: '44'}
           - {os: windows-latest, r: 'oldrel', rtools: '43'}