Remove legacy configuration parsing code, no longer needed with upgrade-borgmatic-config gone (#529).

tests/integration/config/test_legacy.py

@@ -1,18 +0,0 @@
-import string
-from collections import OrderedDict
-from io import StringIO
-
-from borgmatic.config import legacy as module
-
-
-def test_parse_section_options_with_punctuation_should_return_section_options():
-    parser = module.RawConfigParser()
-    parser.read_file(StringIO(f'[section]\nfoo: {string.punctuation}\n'))
-
-    section_format = module.Section_format(
-        'section', (module.Config_option('foo', str, required=True),)
-    )
-
-    config = module.parse_section_options(parser, section_format)
-
-    assert config == OrderedDict((('foo', string.punctuation),))