fix(nvm): node versioning, not semver

lib/manager/nvm/extract.js

-const semver = require('../../versioning/semver');
+const node = require('../../versioning/node');
 
 module.exports = {
   extractPackageFile,
@@ -10,7 +10,7 @@ function extractPackageFile(content) {
     currentValue: content.trim(),
     purl: 'pkg:github/nodejs/node',
   };
-  if (!semver.isVersion(dep.currentValue)) {
+  if (!node.isValid(dep.currentValue)) {
     dep.skipReason = 'unsupported-version';
   }
   return { deps: [dep] };