backend on main still has version 1.17.0dev0

[mattip]

These places still use 1.17.0dev0 as the version, shouldn't they be updated (on main, the release-1.17 branch is correct)?

$ git grep 1.17.0.dev0
doc/source/conf.py:release = '1.17.0.dev0'
setup.py:        version='1.17.0.dev0',
src/c/_cffi_backend.c:#define CFFI_VERSION  "1.17.0.dev0"
src/c/test_c.py:assert __version__ == "1.17.0.dev0", ("This test_c.py file is for testing a version"
src/cffi/__init__.py:__version__ = "1.17.0.dev0"
src/cffi/_embedding.h:                               "\ncompiled with cffi version: 1.17.0.dev0"

[tacaswell]

This would be closed by #112