BLD: update build and runtime dependencies for numpy 2.0 (#715)

Also enable the ruff rule for NumPy 2.0 (nothing to fix, it was all okay
already).

pyproject.toml

@@ -7,23 +7,19 @@
 [build-system]
 build-backend = "mesonpy"
 requires = [
-    "meson-python>=0.14.0",
-    "Cython>=0.29.35",
+    "meson-python>=0.15.0",
+    # The upper bound on Cython is pre-emptive. The conditional compilation
+    # with IF we use in Cython code is deprecated and will be removed from
+    # Cython at some point.
+    "Cython>=3.0.4,<3.1",
 
-    # When numpy 2.0.0rc1 comes out, we should update this to build against 2.0,
-    # and then runtime depend on the range 1.22.X to <2.3. No need to switch to
-    # 1.25.2 in the meantime (1.25.x is the first version which exports older C
-    # API versions by default).
-
-    # default numpy requirements
-    "numpy==1.22.4; python_version<='3.10' and platform_python_implementation != 'PyPy'",
-    "numpy==1.23.3; python_version=='3.11' and platform_python_implementation != 'PyPy'",
-    "numpy==1.26.0; python_version=='3.12' and platform_python_implementation != 'PyPy'",
-    # For Python versions which aren't yet officially supported, we specify an
-    # unpinned NumPy which allows source distributions to be used and allows
-    # wheels to be used as soon as they become available.
-    "numpy; python_version>='3.13'",
-    "numpy; python_version>='3.9' and platform_python_implementation=='PyPy'",
+    # numpy requirement for wheel builds for distribution on PyPI - building
+    # against 2.x yields wheels that are also compatible with numpy 1.x at
+    # runtime.
+    # Note that building against numpy 1.x works fine too - users and
+    # redistributors can do this by installing the numpy version they like and
+    # disabling build isolation.
+    "numpy>=2.0.0b1,<2.3",
 ]
 
 [project]
@@ -37,11 +33,7 @@ maintainers = [
 ]
 description = "PyWavelets, wavelet transform module"
 requires-python = ">=3.9"
-dependencies = [
-    # TODO: update to "pin-compatible" once possible, see
-    # https://github.com/FFY00/meson-python/issues/29
-    "numpy>=1.22.4,<2.0",
-]
+dependencies = ["numpy>=1.22.4,<3"]
 readme = "README.rst"
 classifiers = [
     "Development Status :: 5 - Production/Stable",
@@ -73,6 +65,7 @@ lint.select = [
     'UP',
     'C4',
     'E713',
+    'NPY201',
     'PIE',
     'PGH003',
     'PLR0402',