Issue Hover Card fails for external repository issue reference surrounded by parentheses (#3285)

Fixes #3268

Author: alexr00

src/issues/util.ts

@@ -20,8 +20,8 @@ import { ReviewManager } from '../view/reviewManager';
 import { CODE_PERMALINK, findCodeLinkLocally } from './issueLinkLookup';
 import { StateManager } from './stateManager';
 
-export const ISSUE_EXPRESSION = /(([^\s]+)\/([^\s]+))?(#|GH-)([1-9][0-9]*)($|\b)/;
-export const ISSUE_OR_URL_EXPRESSION = /(https?:\/\/github\.com\/(([^\s]+)\/([^\s]+))\/([^\s]+\/)?(issues|pull)\/([0-9]+)(#issuecomment\-([0-9]+))?)|(([^\s]+)\/([^\s]+))?(#|GH-)([1-9][0-9]*)($|\b)/;
+export const ISSUE_EXPRESSION = /(([A-Za-z0-9_.\-]+)\/([A-Za-z0-9_.\-]+))?(#|GH-)([1-9][0-9]*)($|\b)/;
+export const ISSUE_OR_URL_EXPRESSION = /(https?:\/\/github\.com\/(([^\s]+)\/([^\s]+))\/([^\s]+\/)?(issues|pull)\/([0-9]+)(#issuecomment\-([0-9]+))?)|(([A-Za-z0-9_.\-]+)\/([A-Za-z0-9_.\-]+))?(#|GH-)([1-9][0-9]*)($|\b)/;
 
 export const USER_EXPRESSION: RegExp = /\@([^\s]+)/;