update actions yaml

.gitea/workflows/nuget.yaml

@@ -1,20 +1,24 @@
 name: dotnet-publish-nuget
 on: [push]
+
+env:
+  DOTNET_VERSION: 8.x
+  DOTNET_NUGET_SOURCE_URL: https://git.mworkspace.cn/api/packages/GiteaActionsSample/nuget/index.json 
 jobs:
   Pack-And-Publish:
     runs-on: ubuntu-latest
     steps:
+    - uses: actions/checkout@v3
+    - name: List files in the repos
+      run: ls ${{ gitea.workspace }} && ls $GITEA_WORKSPACE
     - name: Setup .NET Core
-      uses: actions/setup-dotnet@v1
+      uses: actions/setup-dotnet@v3
       with:
-        dotnet-version: 8.x
+        dotnet-version: ${{ env.DOTNET_VERSION }}
         cache: true
-        source-url: https://git.mworkspace.cn/api/packages/GiteaActionsSample/nuget/index.json
+        source-url: ${{ env.DOTNET_NUGET_SOURCE_URL }}
       env:
         NUGET_AUTH_TOKEN: ${{secrets.NUGET_APIKEY}}
-    - name: List files in the repos
-      uses: actions/checkout@v3
-      run: ls ${{ gitea.workspace }} && ls $GITEA_WORKSPACE
     - name: Install dependencies
       run: dotnet restore
     - name: Build