Update/Actions: checkin/out upgrade to v4

.github/actions/upload-plugin/action.yml

@@ -28,8 +28,8 @@ runs:
         mv "${{ inputs.pdbFileName }}" "deploy-${{ inputs.pluginName }}/${{ inputs.pluginName }}/${{ inputs.archFolder }}"
       fi
   - name: Upload plugin
-    uses: actions/upload-artifact@v3
+    uses: actions/upload-artifact@v4
     with:
-      name: ${{ inputs.pluginName }}
+      name: ${{ inputs.pluginName }}-${{ env.platform }}
       path: deploy-${{ inputs.pluginName }}/*   # this way the top folder in the artifacts is "MyPlugin"
       if-no-files-found: error

.github/workflows/build.yml

@@ -20,10 +20,12 @@ jobs:
   #####################################
   # Linux with GCC
   build-lin:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
+    env:
+      platform: lin
     steps:
     - name: Checkout Code
-      uses: actions/checkout@v3       # must checkout before we can use our own actions
+      uses: actions/checkout@v4       # must checkout before we can use our own actions
       with:
         submodules: 'recursive'
     - name: Build
@@ -42,10 +44,12 @@ jobs:
   #####################################
   # MacOS with CMake/clang and sign/notarize in self-written script
   build-mac:
-    runs-on: macos-latest
+    runs-on: macos-12
+    env:
+      platform: mac
     steps:
     - name: Checkout Code
-      uses: actions/checkout@v3       # must checkout before we can use our own actions
+      uses: actions/checkout@v4       # must checkout before we can use our own actions
       with:
         submodules: 'recursive'
     - name: Build
@@ -86,9 +90,11 @@ jobs:
   # Windows with MS Visual Studio
   build-win:
     runs-on: windows-2022
+    env:
+      platform: win
     steps:
     - name: Checkout Code
-      uses: actions/checkout@v3       # must checkout before we can use our own actions
+      uses: actions/checkout@v4       # must checkout before we can use our own actions
       with:
         submodules: 'recursive'
     - name: Build