fix(test): Fix the validation test failure.

The metrics doc url was updated to https://raw.githubusercontent.com/mozilla/application-services/master/docs/product-portal/accounts/metrics.md.

fixes #6934

tests/server/validation.js

@@ -9,7 +9,7 @@ const { registerSuite } = intern.getInterface('object');
 const request = require('request-promise');
 const validation = require('../../server/lib/validation');
 
-const METRICS_DOCS_URL = 'https://raw.githubusercontent.com/mozilla/application-services/master/docs/accounts/metrics.md';
+const METRICS_DOCS_URL = 'https://raw.githubusercontent.com/mozilla/application-services/master/docs/product-portal/accounts/metrics.md';
 const UTM_REGEX = validation.TYPES.UTM._tests[1].arg.pattern;
 const REGEXES = new Map([
   [ 'entrypoint', validation.PATTERNS.ENTRYPOINT ],