Remove requirement to update version manually from release checklist.

Author: rhpvorderman

.github/release_checklist.md

@@ -8,7 +8,6 @@ Release checklist
 from CHANGELOG.rst.
 - [ ] Push tag to remote. This triggers the wheel/sdist build on github CI.
 - [ ] merge `main` branch back into `develop`.
-- [ ] Add updated version number to develop. (`setup.py` and `src/zlib_ng/__init__.py`)
 - [ ] Build the new tag on readthedocs. Only build the last patch version of
 each minor version. So `1.1.1` and `1.2.0` but not `1.1.0`, `1.1.1` and `1.2.0`.
 - [ ] Create a new release on github.