Fix compiling webhost failure in all pipelines

Author: YunchuWang

setup.py

@@ -412,7 +412,8 @@ def _compile_webhost(webhost_dir: pathlib.Path):
 
         try:
             subprocess.run(
-                args=["dotnet", "build", "WebJobs.Script.sln", "-o", "bin"],
+                args=["dotnet", "build", "WebJobs.Script.sln", "-o", "bin", 
+                      "/p:TreatWarningsAsErrors=false],
                 check=True,
                 cwd=str(webhost_dir),
                 stdout=sys.stdout,