Do not clean up bridge files.

For consistency with how we treat other release artefacts such as
subsets, we should not forcefully clean bridge files.

Author: gouttegd

template/src/ontology/Makefile.jinja2

@@ -448,7 +448,7 @@ check_rdfxml_assets: $(foreach product,$(MAIN_PRODUCTS),check_rdfxml_$(product).
 KEEPRELATIONS=keeprelations.txt
 {% endif -%}
 
-CLEANFILES=$(MAIN_FILES) $(BRIDGE_FILES) $(SRCMERGED) $(EDIT_PREPROCESSED)
+CLEANFILES=$(MAIN_FILES) $(SRCMERGED) $(EDIT_PREPROCESSED)
 
 # This should be executed by the release manager whenever time comes to make a release.
 # It will ensure that all assets/files are fresh, and will copy to release folder