Update changelog

CHANGELOG.rst

@@ -1,3 +1,25 @@
+1.8.0 (UNRELEASED)
+-------------------------
+
+- Rename ``RemoteCallbacks.progress`` callback to ``.sideband_progress``
+  `#1120 <https://github.com/libgit2/pygit2/pull/1120>`_
+
+- New ``Repository.merge_base_many`` and ``Repository.merge_base_octopus``
+  `#1112 <https://github.com/libgit2/pygit2/pull/1112>`_
+
+- New ``Repository.listall_stashes``
+  `#1117 <https://github.com/libgit2/pygit2/pull/1117>`_
+
+- Code cleanup
+  `#1118 <https://github.com/libgit2/pygit2/pull/1118>`_
+
+Backward incompatible changes:
+
+- The ``RemoteCallbacks.progress`` callback has been renamed to
+  ``RemoteCallbacks.sideband_progress``. This matches the documentation, but
+  may break existing code that still uses the old name.
+
+
 1.7.2 (2021-12-06)
 -------------------------