ci: fix compiling webhost failure in all pipelines (#1477)

* Fix compiling webhost failure in all pipelines

* Update setup.py

* Update setup.py

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,