Fix duplicate docstring attributes caused by napoleon and autodoc (open-telemetry#4920)

Co-authored-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>

Author: chimchim89

docs/conf.py

@@ -202,6 +202,10 @@
     "exclude-members": ",".join(_exclude_members),
 }
 
+# Napoleon configuration to avoid duplication with autodoc for dataclass fields
+# Use ivar (instance variable) style for documenting attributes
+napoleon_use_ivar = True
+
 # -- Options for HTML output -------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/exemplar/exemplar.py

@@ -26,7 +26,7 @@ class Exemplar:
     was recorded, for example the span and trace ID of the active span when the
     exemplar was recorded.
 
-    Attributes
+    Attributes:
         trace_id: (optional) The trace associated with a recording
         span_id: (optional) The span associated with a recording
         time_unix_nano: The time of the observation
@@ -38,11 +38,6 @@ class Exemplar:
         https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/sdk.md#exemplar
     """
 
-    # TODO Fix doc - if using valid Google `Attributes:` key, the attributes are duplicated
-    # one will come from napoleon extension and the other from autodoc extension. This
-    # will raise an sphinx error of duplicated object description
-    # See https://github.com/sphinx-doc/sphinx/issues/8664
-
     filtered_attributes: Attributes
     value: Union[int, float]
     time_unix_nano: int

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/measurement.py

@@ -25,19 +25,14 @@ class Measurement:
     """
     Represents a data point reported via the metrics API to the SDK.
 
-    Attributes
+    Attributes:
         value: Measured value
         time_unix_nano: The time the API call was made to record the Measurement
         instrument: The instrument that produced this `Measurement`.
         context: The active Context of the Measurement at API call time.
         attributes: Measurement attributes
     """
 
-    # TODO Fix doc - if using valid Google `Attributes:` key, the attributes are duplicated
-    # one will come from napoleon extension and the other from autodoc extension. This
-    # will raise an sphinx error of duplicated object description
-    # See https://github.com/sphinx-doc/sphinx/issues/8664
-
     value: Union[int, float]
     time_unix_nano: int
     instrument: Instrument