Bump zope-interface from 6.4 to 6.4.post2

Bumps [zope-interface](https://github.com/zopefoundation/zope.interface) from 6.4 to 6.4.post2.
- [Changelog](https://github.com/zopefoundation/zope.interface/blob/master/CHANGES.rst)
- [Commits](zopefoundation/zope.interface@6.4...6.4.post2)

---
updated-dependencies:
- dependency-name: zope-interface
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,3 +1,3 @@
 setuptools<70
 zc.buildout==3.0.1
-zope.interface==6.4
+zope.interface==6.4.post2