Bump to 9.0.0 final

Author: AA-Turner

CHANGES.rst

@@ -1,5 +1,5 @@
-Release 9.0.0 (in development)
-==============================
+Release 9.0.0 (released Nov 30, 2025)
+=====================================
 
 Dependencies
 ------------

sphinx/__init__.py

@@ -11,7 +11,7 @@
 if TYPE_CHECKING:
     from typing import Final
 
-__version__: Final = '9.0.0rc4'
+__version__: Final = '9.0.0'
 __display_version__: Final = __version__  # used for command line version
 
 #: Version info for better programmatic use.
@@ -22,12 +22,12 @@
 #:
 #: .. versionadded:: 1.2
 #:    Before version 1.2, check the string ``sphinx.__version__``.
-version_info: Final = (9, 0, 0, 'candidate', 4)
+version_info: Final = (9, 0, 0, 'final', 0)
 
 package_dir: Final = _StrPath(__file__).resolve().parent
 del _StrPath
 
-_in_development = True
+_in_development = False
 if _in_development:
     # Only import subprocess if needed
     import subprocess