Increment version to 1.3.0 and set release date in changelog

Also make Cython pinning more strict for older Python versions where
old Numpy and new Cython causes build problems, and exclude wheelhouse
directory containing manylinux wheels from sdist.

Author: jacklovell

CHANGELOG.md

@@ -1,7 +1,7 @@
 Project Changelog
 =================
 
-Release 1.3.0 (TBD)
+Release 1.3.0 (9 Sep 2025)
 -------------------
 
 * Support Cherab 1.5 (#74).

pyproject.toml

@@ -2,7 +2,10 @@
 requires = [
     "scikit-build-core",
     # "cython-cmake",  # Vendored to support Python 3.7 builds.
-    "cython~=3.0",
+    # Oldest supported numpy for Python <3.9 missing pxd files which
+    # are provided by Cython < 3.1 (see Cython GH #5842).
+    "cython~=3.0.0; python_version < '3.9'",
+    "cython~=3.0; python_version >= '3.9'",
     # "oldest-supported-numpy; python_version < '3.9'",
     # "numpy~=2.0; python_version >= '3.9'",
     # Cherab currently requires numpy < 2, so this package does too.
@@ -14,7 +17,7 @@ build-backend="scikit_build_core.build"
 
 [project]
 name = "cherab-solps"
-version = "1.3.0rc1"
+version = "1.3.0"
 dependencies = [
     "raysect == 0.8.1.*",
     "cherab == 1.5.*",
@@ -50,6 +53,7 @@ sdist.exclude = [
     ".github",
     ".gitignore",
     "dev",
+    "wheelhouse",
 ]
 wheel.exclude = [
     "**.pyx",