[CSharp/aspnetcore] Mark platform tests as stripped (#10611)

ASP netcore hardcodes HTTP headers for the platform tests, so these
tests should be marked as stripped:

https://github.com/TechEmpower/FrameworkBenchmarks/blob/d36a2ede0db5c69d70da421e2f48aea53973c0c5/frameworks/CSharp/aspnetcore/src/Platform/BenchmarkApplication.Plaintext.cs#L12-L16

Author: p8

frameworks/CSharp/aspnetcore/benchmark_config.json

@@ -12,7 +12,7 @@
         "update_url": "/updates/",
         "cached_query_url": "/cached-worlds/",
         "port": 8080,
-        "approach": "Realistic",
+        "approach": "Stripped",
         "classification": "Platform",
         "database": "Postgres",
         "framework": "ASP.NET Core [Platform]",
@@ -35,7 +35,7 @@
         "update_url": "/updates/",
         "cached_query_url": "/cached-worlds/",
         "port": 8080,
-        "approach": "Realistic",
+        "approach": "Stripped",
         "classification": "Platform",
         "database": "Postgres",
         "framework": "ASP.NET Core [Platform]",
@@ -101,7 +101,7 @@
         "update_url": "/updates/",
         "cached_query_url": "/cached-worlds/",
         "port": 8080,
-        "approach": "Realistic",
+        "approach": "Stripped",
         "classification": "Platform",
         "database": "MySQL",
         "framework": "ASP.NET Core [Platform]",