Mark QgsProcessingModelAlgorithm as non-stable API

We want to be able to extend this in future without any
stable API contract.

Author: nyalldawson

python/core/processing/qgsprocessingmodelalgorithm.sip

@@ -829,6 +829,7 @@ Copies are protected to avoid slicing
 
 
 
+
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *

src/core/processing/qgsprocessingmodelalgorithm.cpp

@@ -24,6 +24,8 @@
 #include <QFile>
 #include <QTextStream>
 
+///@cond NOT_STABLE
+
 QgsProcessingModelAlgorithm::ChildAlgorithm::ChildAlgorithm( const QString &algorithmId )
   : mAlgorithmId( algorithmId )
 {
@@ -1188,3 +1190,5 @@ bool QgsProcessingModelAlgorithm::ModelParameter::loadVariant( const QVariantMap
   restoreCommonProperties( map );
   return true;
 }
+
+///@endcond

src/core/processing/qgsprocessingmodelalgorithm.h

@@ -22,6 +22,7 @@
 #include "qgis.h"
 #include "qgsprocessingalgorithm.h"
 
+///@cond NOT_STABLE
 
 /**
  * \class QgsProcessingModelAlgorithm
@@ -858,6 +859,8 @@ class CORE_EXPORT QgsProcessingModelAlgorithm : public QgsProcessingAlgorithm
     friend class TestQgsProcessing;
 };
 
+///@endcond
+
 #endif // QGSPROCESSINGMODELALGORITHM_H