Hide DesignBlock Migrate Libraries button (for now).

There aren't (yet) any legacy libraries to migrate.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/19360

common/dialogs/panel_design_block_lib_table.cpp

@@ -310,6 +310,9 @@ PANEL_DESIGN_BLOCK_LIB_TABLE::PANEL_DESIGN_BLOCK_LIB_TABLE( DIALOG_EDIT_LIBRARY_
 
     wxArrayString choices;
 
+    // There aren't (yet) any legacy DesignBlock libraries to migrate
+    m_migrate_libs_button->Hide();
+
     for( auto& [fileType, desc] : m_supportedDesignBlockFiles )
         choices.Add( DESIGN_BLOCK_IO_MGR::ShowType( fileType ) );
 

common/dialogs/panel_design_block_lib_table_base.cpp

@@ -1,5 +1,5 @@
 ///////////////////////////////////////////////////////////////////////////
-// C++ code generated with wxFormBuilder (version 3.10.1-0-g8feb16b)
+// C++ code generated with wxFormBuilder (version 4.2.1-0-g80c4cb6)
 // http://www.wxformbuilder.org/
 //
 // PLEASE DO *NOT* EDIT THIS FILE!

common/dialogs/panel_design_block_lib_table_base.h

@@ -1,5 +1,5 @@
 ///////////////////////////////////////////////////////////////////////////
-// C++ code generated with wxFormBuilder (version 3.10.1-0-g8feb16b)
+// C++ code generated with wxFormBuilder (version 4.2.1-0-g80c4cb6)
 // http://www.wxformbuilder.org/
 //
 // PLEASE DO *NOT* EDIT THIS FILE!
@@ -32,7 +32,6 @@ class WX_GRID;
 
 ///////////////////////////////////////////////////////////////////////////
 
-
 ///////////////////////////////////////////////////////////////////////////////
 /// Class PANEL_DESIGN_BLOCK_LIB_TABLE_BASE
 ///////////////////////////////////////////////////////////////////////////////