Merge pull request #3173 from stan-dev/rtools45-ci

Update windows CI to use rtools45

Author: WardBrian

.github/workflows/main.yml

@@ -45,11 +45,11 @@ jobs:
       if: runner.os == 'Windows'
       with:
         r-version: 'release'
-        rtools-version: '44'
+        rtools-version: '45'
 
-    - name: Set path for Rtools44
+    - name: Set path for Rtools45
       if: runner.os == 'Windows'
-      run: echo "C:/rtools44/usr/bin;C:/rtools44/x86_64-w64-mingw32.static.posix/bin" | Out-File -Append -FilePath $env:GITHUB_PATH -Encoding utf8
+      run: echo "C:/rtools45/usr/bin;C:/rtools45/x86_64-w64-mingw32.static.posix/bin" | Out-File -Append -FilePath $env:GITHUB_PATH -Encoding utf8
 
     - name: Build Math libs
       shell: pwsh
@@ -93,11 +93,11 @@ jobs:
       if: runner.os == 'Windows'
       with:
         r-version: 'release'
-        rtools-version: '44'
+        rtools-version: '45'
 
-    - name: Set path for Rtools44
+    - name: Set path for Rtools45
       if: runner.os == 'Windows'
-      run: echo "C:/rtools44/usr/bin;C:/rtools44/x86_64-w64-mingw32.static.posix/bin" | Out-File -Append -FilePath $env:GITHUB_PATH -Encoding utf8
+      run: echo "C:/rtools45/usr/bin;C:/rtools45/x86_64-w64-mingw32.static.posix/bin" | Out-File -Append -FilePath $env:GITHUB_PATH -Encoding utf8
 
     - name: Build Math libs
       shell: pwsh