chore: prepare for 2.9

Author: henryiii

docs/changelog.rst

@@ -7,8 +7,8 @@ Starting with version 1.8.0, pybind11 releases use a `semantic versioning
 <http://semver.org>`_ policy.
 
 
-IN DEVELOPMENT
---------------
+Version 2.9.0 (Dec 28, 2021)
+----------------------------
 
 This is the last version to support Python 2.7 and 3.5.
 

include/pybind11/detail/common.h

@@ -11,11 +11,11 @@
 
 #define PYBIND11_VERSION_MAJOR 2
 #define PYBIND11_VERSION_MINOR 9
-#define PYBIND11_VERSION_PATCH 0.dev1
+#define PYBIND11_VERSION_PATCH 0
 
 // Similar to Python's convention: https://docs.python.org/3/c-api/apiabiversion.html
 // Additional convention: 0xD = dev
-#define PYBIND11_VERSION_HEX 0x020900D1
+#define PYBIND11_VERSION_HEX 0x02090000
 
 #define PYBIND11_NAMESPACE_BEGIN(name) namespace name {
 #define PYBIND11_NAMESPACE_END(name) }

pybind11/_version.py

@@ -8,5 +8,5 @@ def _to_int(s):
         return s
 
 
-__version__ = "2.9.0.dev1"
+__version__ = "2.9.0"
 version_info = tuple(_to_int(s) for s in __version__.split("."))