Remove use of distutils

This has been removed in Python 3.12, which is preventing us using
osc-placement in those environments. Thankfully we only use it for
StrictVersion which we are using to parse microversions. This is
actually overkill here since we can always expect a version string like
'1.5', thus we do this parsing ourselves rather than drag in a new
library like 'microversion_parse'.

Change-Id: I2923238f8b30568bceb1799882d4468ff1d7e538
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

osc_placement/tests/unit/test_version.py

@@ -70,7 +70,7 @@ class TestVersion(base.BaseTestCase):
         self.assertRaisesRegex(
             ValueError,
             'Operation or argument is not supported',
-            version.compare, '3.1.2', version.gt('3.1.3'))
+            version.compare, '3.1', version.gt('3.2'))
 
     def test_check_decorator(self):
         fake_api = mock.Mock()

osc_placement/version.py

@@ -10,8 +10,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from distutils.version import StrictVersion
+import functools
 import operator
+import re
 
 
 NEGOTIATE_VERSIONS = [
@@ -60,8 +61,29 @@ SUPPORTED_VERSIONS = SUPPORTED_MICROVERSIONS + NEGOTIATE_VERSIONS
 MAX_VERSION_NO_GAP = '1.29'
 
 
+@functools.total_ordering
+class _Version:
+    _version_re = re.compile(r'^(\d) \. (\d+)$', re.VERBOSE | re.ASCII)
+
+    def __init__(self, version):
+        match = self._version_re.match(version)
+        if not match:
+            raise ValueError('invalid version number %s' % version)
+        major, minor = match.group(1, 2)
+        self.version = (int(major), int(minor))
+
+    def __str__(self):
+        return '.'.join(str(v) for v in self.version)
+
+    def __eq__(self, other):
+        return self.version == other.version
+
+    def __lt__(self, other):
+        return self.version < other.version
+
+
 def _op(func, b, msg):
-    return lambda a: func(StrictVersion(a), StrictVersion(b)) or msg
+    return lambda a: func(_Version(a), _Version(b)) or msg
 
 
 def lt(b):