Update pyproject.toml: try and keep Python 3.8 support

pyproject.toml

@@ -14,7 +14,8 @@ requires = [
     "setuptools_scm[toml]>=6.2",
     "wheel", # ephem package likes to have wheel installed
     "cython",
-    "numpy>=2.0.0",
+    'numpy>=2.0.0; python_version > "3.8"',
+    'numpy<2.0; python_version == "3.8",
 ]
 build-backend = "setuptools.build_meta"
 
@@ -32,6 +33,7 @@ classifiers=[
     "Operating System :: MacOS",
     "Operating System :: POSIX :: Linux",
     "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
@@ -41,9 +43,10 @@ dynamic = [
     "version",
 ]
 
-requires-python = ">=3.9, <4"
+requires-python = ">=3.8, <4"
 dependencies = [
-    "numpy",
+    'numpy<2.0; python_version == "3.8"',
+    'numpy; python_version > "3.8"',
     "scipy",
     "matplotlib",
     "ephem",