Update secret-scanning.yml

Added .net 6.0 for credscan to run

Author: theangrytech-git

.github/workflows/secret-scanning.yml

@@ -24,6 +24,11 @@ jobs:
       - name: Set tool to only run secret scan
         run: echo "TOOLS=credscan" >> $GITHUB_ENV
 
+      - name: Setup .NET 6 SDK
+        uses: actions/setup-dotnet@v3
+        with:
+          dotnet-version: 6.0.x        
+
       - name: Run Microsoft Security DevOps - Secret Scan
         uses: theangrytech-git/security-devops-action@main
         id: msdo