Install dotnet 5 on CI/CD so that source generators work

.github/workflows/CD.yml

@@ -13,11 +13,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2.3.3
 
-      - name: Install .NET
+      - name: Install .NET (v3.1)
         uses: actions/setup-dotnet@v1.7.2
         with:
           dotnet-version: 3.1.x
 
+      - name: Install .NET (v5.0)
+        uses: actions/setup-dotnet@v1.7.2
+        with:
+          dotnet-version: 5.0.x
+
       - name: Build & publish (CLI)
         run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release
 

.github/workflows/CI.yml

@@ -10,11 +10,16 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2.3.3
 
-      - name: Install .NET
+      - name: Install .NET (v3.1)
         uses: actions/setup-dotnet@v1.7.2
         with:
           dotnet-version: 3.1.x
 
+      - name: Install .NET (v5.0)
+        uses: actions/setup-dotnet@v1.7.2
+        with:
+          dotnet-version: 5.0.x
+
       - name: Build & publish (CLI)
         run: dotnet publish DiscordChatExporter.Cli/ -o DiscordChatExporter.Cli/bin/Publish/ --configuration Release