importer: Remove separate define/seal step for importing modules
importer: Remove separate define/seal step for importing modules

If we simply set the module in the importer as the last step, this
can't possibly fail.

pixunil/cjs,mtwebster/cjs,mtwebster/cjs,mtwebster/cjs,endlessm/gjs,mtwebster/cjs,mtwebster/cjs,pixunil/cjs,endlessm/gjs,pixunil/cjs,pixunil/cjs,endlessm/gjs,pixunil/cjs,endlessm/gjs,endlessm/gjs