chore: Update XPMP2 again, and Github Action versions

Author: TwinFan

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

@@ -28,7 +28,7 @@ runs:
         mv "${{ inputs.pdbFileName }}" "deploy-${{ inputs.pluginName }}/${{ inputs.pluginName }}/${{ inputs.archFolder }}"
       fi
   - name: Upload plugin
-    uses: actions/upload-artifact@v4
+    uses: actions/upload-artifact@v6
     with:
       name: ${{ inputs.pluginName }}-${{ env.platform }}
       path: deploy-${{ inputs.pluginName }}/*   # this way the top folder in the artifacts is "MyPlugin"

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
       platform: lin
     steps:
     - name: Checkout Code
-      uses: actions/checkout@v4       # must checkout before we can use our own actions
+      uses: actions/checkout@v5       # must checkout before we can use our own actions
       with:
         submodules: 'recursive'
     - name: Build
@@ -50,7 +50,7 @@ jobs:
       platform: mac
     steps:
     - name: Checkout Code
-      uses: actions/checkout@v4       # must checkout before we can use our own actions
+      uses: actions/checkout@v5       # must checkout before we can use our own actions
       with:
         submodules: 'recursive'
     - name: Build
@@ -96,7 +96,7 @@ jobs:
       platform: win
     steps:
     - name: Checkout Code
-      uses: actions/checkout@v4       # must checkout before we can use our own actions
+      uses: actions/checkout@v5       # must checkout before we can use our own actions
       with:
         submodules: 'recursive'
     - name: Build