fix tests

Author: memsharded

conan/cps/cps.py

@@ -95,7 +95,7 @@ def from_cpp_info(cpp_info, conanfile, libname=None):
         cps_comp.link_location = cpp_info.link_location
         cps_comp.link_libraries = cpp_info.system_libs
         langs = {"C": "c", "C++": "cpp"}
-        cps_comp.link_languages = [langs[lang] for lang in cpp_info.languages]
+        cps_comp.link_languages = [langs[lang] for lang in cpp_info.languages or []]
         required = cpp_info.requires
         cps_comp.requires = [f":{c}" if "::" not in c else c.replace("::", ":") for c in required]
         return cps_comp