Update pyproject.toml to remove python 3.9.

Author: janiversen

pyproject.toml

@@ -22,15 +22,14 @@ classifiers = [
     "Operating System :: MacOS :: MacOS X",
     "Operating System :: OS Independent",
     "Operating System :: Microsoft",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Topic :: System :: Networking",
     "Topic :: Utilities",
 ]
-requires-python = ">=3.9.0"
+requires-python = ">=3.10.0"
 
 [project.urls]
 Homepage = "https://github.com/pymodbus-dev/pymodbus/"