Use version of Simon's install script

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

@@ -48,8 +48,13 @@ jobs:
 
       - name: Install macOS jpeg dependency
         if: runner.os == 'macOS'
-        run: brew install libjpeg
-
+        run: |
+          ARCH=`uname -m`
+          if [ ! -e /opt/R/$ARCH ]; then sudo mkdir -p /opt/R/$ARCH; sudo chown -R $USER /opt/R; fi
+          Rscript -e 'dep="jpeg"; source("https://mac.R-project.org/bin/install.R"); install.libs(dep)'
+          if ! echo $PATH | grep /opt/R/$ARCH/bin >/dev/null; then echo /opt/R/$ARCH/bin > newPATH; cat $GITHUB_PATH >> newPATH; cat newPATH > $GITHUB_PATH; fi
+        shell: bash
+
       - uses: r-lib/actions/setup-r-dependencies@v2
 
         with: