Nightly: use dev rig on macos for sonoma R-devel arm64 builds

[ci skip]

Author: gaborcsardi

.github/workflows/nightly.yaml

@@ -104,8 +104,8 @@ jobs:
 
     - name: Install rig
       run: |
-        brew tap r-lib/rig
-        brew install r-lib/rig/rig
+        curl -LO https://github.com/r-lib/rig/releases/download/v0.8.0-beta2/rig-0.8.0-beta2-macOS-arm64.pkg
+        sudo installer -pkg rig*.pkg -target /
 
     - uses: r-hub/actions/setup-r-sysreqs@main
       with:
@@ -160,8 +160,8 @@ jobs:
 
     - name: Install rig
       run: |
-        brew tap r-lib/rig
-        brew install r-lib/rig/rig
+        curl -LO https://github.com/r-lib/rig/releases/download/v0.8.0-beta2/rig-0.8.0-beta2-macOS-arm64.pkg
+        sudo installer -pkg rig*.pkg -target /
 
     - uses: r-hub/actions/setup-r-sysreqs@main
       with: