remove deprecated "borg verify"

use borg extract --dry-run ...

borg/archiver.py

@@ -755,9 +755,6 @@ class Archiver:
             ('--do-not-cross-mountpoints', '--one-file-system',
              'Warning:  "--do-no-cross-mountpoints" has been deprecated. Use "--one-file-system" instead.'),
         ]
-        if args and args[0] == 'verify':
-            print('Warning: "borg verify" has been deprecated. Use "borg extract --dry-run" instead.')
-            args = ['extract', '--dry-run'] + args[1:]
         for i, arg in enumerate(args[:]):
             for old_name, new_name, warning in deprecations:
                 if arg.startswith(old_name):

borg/testsuite/archiver.py

@@ -826,8 +826,6 @@ class ArchiverTestCase(ArchiverTestCaseBase):
         self.create_regular_file('file1', size=1024 * 80)
         self.cmd('init', self.repository_location)
         self.cmd('create', self.repository_location + '::test', 'input')
-        output = self.cmd('verify', '-v', self.repository_location + '::test')
-        self.assert_in('"borg verify" has been deprecated', output)
         output = self.cmd('prune', self.repository_location, '--hourly=1')
         self.assert_in('"--hourly" has been deprecated. Use "--keep-hourly" instead', output)