changelog: update back to 6.3.0 after making things work

CHANGELOG.rst

@@ -1,10 +1,10 @@
 
-v7.0.0
+6.3.0
 =======
 
 .. warning::
 
-   This release explicitly raises errors on unsupported setuptools.
+   This release explicitly warns on unsupported setuptools.
    This unfortunately has to happen as the legacy ``setup_requires`` mechanism
    incorrectly configures the setuptools working-set when a more recent setuptools
    version than available is required.
@@ -20,7 +20,7 @@ v7.0.0
 * fix #612: depend on packaging to ensure version parsing parts
 * fix #611: correct the typo that hid away the toml extra and add it in ``setup.py`` as well
 * fix #615: restore support for the git_archive plugin which doesn't pass over the config
-
+* restore the ability to run on old setuptools while to avoid breaking pipelines
 
 v6.2.0
 =======