Update to .NET 5 RTM

.github/workflows/codeql-analysis.yml

@@ -33,17 +33,8 @@ jobs:
 
     # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
-    # - name: Autobuild
-    #  uses: github/codeql-action/autobuild@v1
-
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: 5.0.100-rc.1.20452.10
-    - name: Install dependencies
-      run: dotnet restore
-    - name: Build
-      run: dotnet build --configuration Release --no-restore
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 https://git.io/JvXDl