docs: deprecate SensorDataSeries and SensorDataSeriesList for removal in v4.0.0

The single-channel (.osi) and multi-channel (.mcap) trace file formats
have fully superseded these messages:

- .osi traces generalize SensorDataSeries to any top-level message type
  and support streaming without loading all timesteps into memory.
- .mcap traces generalize SensorDataSeriesList to any combination of
  top-level message types with metadata, schemas, compression, and
  random access.

Internal buffering by sensor models is an implementation concern and
does not belong in the interface specification.

Resolves #900

Signed-off-by: Carlo van Driesten <carlo.van-driesten@bmw.de>

Author: jdsika

osi_datarecording.proto

@@ -7,8 +7,16 @@ import "osi_sensordata.proto";
 package osi3;
 
 //
-// \brief (Time) Series of \c SensorData messages that may be used for data
-// recording or internal buffering by some sensor models.
+// \brief (Time) Series of \c SensorData messages.
+//
+// \attention This message is deprecated and will be removed in OSI 4.0.0.
+// The single-channel OSI trace file format (.osi) supersedes
+// this message for recording purposes. It generalizes the concept
+// to any top-level message type and supports streaming without
+// requiring all timesteps to be held in memory at once.
+// Internal buffering by sensor models should be handled within
+// the sensor model implementation, not through the interface
+// specification.
 //
 message SensorDataSeries
 {
@@ -21,6 +29,12 @@ message SensorDataSeries
 // \brief List of sensors where each element contains a time series of
 // \c SensorData messages.
 //
+// \attention This message is deprecated and will be removed in OSI 4.0.0.
+// The multi-channel OSI trace file format (.mcap) supersedes
+// this message for recording purposes. It generalizes the concept
+// to any combination of top-level message types and provides
+// metadata, schema records, compression, and random access.
+//
 message SensorDataSeriesList
 {
     // List of sensor data for multiple sensors at subsequent time steps.