fix(pep440): add isVersion check before equals

lib/versioning/pep440/index.ts

@@ -19,7 +19,7 @@ const {
   major: getMajor,
   minor: getMinor,
   patch: getPatch,
-  eq: equals,
+  eq,
 } = pep440;
 
 const isStable = (input: string): boolean => {
@@ -50,6 +50,10 @@ export const isSingleVersion = (constraint: string): string =>
 
 export { isVersion, matches };
 
+const equals = (version1: string, version2: string): boolean => {
+  return isVersion(version1) && isVersion(version2) && eq(version1, version2);
+};
+
 export const api: VersioningApi = {
   equals,
   getMajor,