Exclude database libraries from the symbol library editor

These libraries are metadata libraries and it does not make sense
to have them be shown in the symbol editor

Fixes https://gitlab.com/kicad/code/kicad/-/issues/12842
Fixes https://gitlab.com/kicad/code/kicad/-/issues/12878

eeschema/symbol_library_manager.cpp

@@ -134,7 +134,13 @@ wxArrayString SYMBOL_LIBRARY_MANAGER::GetLibraryNames() const
     wxArrayString res;
 
     for( const wxString& libName : symTable()->GetLogicalLibs() )
+    {
+        // Database libraries are hidden from the symbol editor at the moment
+        if( GetLibrary( libName )->SchLibType() == SCH_IO_MGR::SCH_DATABASE )
+            continue;
+
         res.Add( libName );
+    }
 
     return res;
 }