[cleanup] Remove deprecated geomechancis coupling manager interface

dumux/geomechanics/poroelastic/couplingmanager.hh

@@ -350,12 +350,6 @@ public:
                                                                         poroMechLocalAssembler.elemBcTypes());
     }
 
-    //! Return the coupling context (used in mechanical sub-problem to compute effective pressure)
-    [[deprecated("Obtain the volume variables directly calling getPMFlowVolVars(element). Will be removed after 3.1!")]]
-    const PoroMechanicsCouplingContext& poroMechanicsCouplingContext() const
-    { return poroMechCouplingContext_; }
-
-
     //! Return the porous medium flow variables an element/scv of the poromech domain couples to
     const VolumeVariables<PMFlowId>& getPMFlowVolVars(const Element<PoroMechId>& element) const
     {