Use .NET 8 SDK to build YARP .NET 7 runs (#1844)

Author: MihaZupan

build/proxies-scenarios.yml

@@ -30,7 +30,7 @@ parameters:
     condition: 'true'
   - displayName: YARP-net70
     scenario: proxy-yarp
-    arguments: $(proxyJobs) --property proxy=yarp-net70 --application.framework net7.0
+    arguments: $(proxyJobs) --property proxy=yarp-net70 --application.framework net7.0 --application.noGlobalJson true
     supportsHttp: true
     supportsServerHttps: true
     supportsServerHttp2: true