Prepare PR for review: set dotnet to missing_feature, clean up docstring

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: link04

manifests/dotnet.yml

@@ -1124,7 +1124,7 @@ manifest:
   tests/test_library_conf.py::Test_HeaderTags_Wildcard_Response_Headers: missing_feature
   tests/test_library_logs.py::Test_NoExceptions::test_java_logs: irrelevant (only for Java)
   tests/test_library_logs.py::Test_NoExceptions::test_java_telemetry_logs: irrelevant (only for Java)
-  tests/test_otlp_runtime_metrics.py::Test_OtlpRuntimeMetrics: v3.42.0
+  tests/test_otlp_runtime_metrics.py::Test_OtlpRuntimeMetrics: missing_feature
   tests/test_profiling.py::Test_Profile:
     - weblog_declaration:
         "*": v1.0  # real version not known

tests/test_otlp_runtime_metrics.py

@@ -4,12 +4,6 @@
 libraries should send runtime metrics via OTLP with OTel-native naming (dotnet.*,
 jvm.*, go.*, v8js.*, etc.) instead of DD-proprietary naming (runtime.dotnet.*,
 runtime.go.*, runtime.node.*, etc.).
-
-Related PRs:
-- .NET: https://github.com/DataDog/dd-trace-dotnet/pull/8299
-- Go: https://github.com/DataDog/dd-trace-go/pull/4611
-- Node.js: https://github.com/DataDog/dd-trace-js/pull/7869
-- Java: https://github.com/DataDog/dd-trace-java/pull/10985
 """
 
 from utils import context, features, interfaces, scenarios, weblog