debuglock: ignore ENOENT error when unlocking

This is consistent with the main `lock.release` code.

Differential Revision: https://phab.mercurial-scm.org/D12481

mercurial/debugcommands.py

@@ -2148,9 +2148,9 b' def debuglocks(ui, repo, **opts):'
     """
 
     if opts.get('force_free_lock'):
-        repo.svfs.unlink(b'lock')
+        repo.svfs.tryunlink(b'lock')
     if opts.get('force_free_wlock'):
-        repo.vfs.unlink(b'wlock')
+        repo.vfs.tryunlink(b'wlock')
     if opts.get('force_free_lock') or opts.get('force_free_wlock'):
         return 0