refactor!: migrate to modern numpy API, patch root solving, and bump dependencies

- Drop support for Python 3.8.
- Bump minimum dependencies to `numpy>=2.0` and `numba>=0.60`.
- Replace legacy NumPy polynomial functions (polyder, polyadd, etc.) with
  the modern `numpy.polynomial.Polynomial` class for stable calculus and
  arithmetic operations.
- Remove `_strip_leading_zeros` as the modern API handles degree alignment
  and zero-trimming natively.
- Retain highest-to-lowest `self.coefficients` array to maintain compatibility
  with Numba and CUDA GPU kernels evaluating via Horner's method.
- Fix `TypeError` in `quadratic_solve` by evaluating `b.real >= 0` to safely
  support complex coefficients.
- Update `quadratic_solve` return type hint to `np.ndarray`.

pyproject.toml

@@ -5,14 +5,14 @@ build-backend = "setuptools.build_meta"
 [project]
 # --- Core Metadata ---
 name = "polysolve"
-version = "0.7.1"
+version = "0.8.0"
 authors = [
   { name="Jonathan Rampersad", email="[email protected]" },
 ]
 description = "A Python library for representing, manipulating, and solving exponential functions using analytical methods and genetic algorithms, with optional CUDA acceleration."
 readme = "README.md"
-requires-python = ">=3.8"
-license = { file="LICENSE" }
+requires-python = ">=3.10"
+license = { file = "LICENSE" }
 keywords = ["math", "polynomial", "genetic algorithm", "cuda", "equation solver"]
 
 # --- Classifiers ---
@@ -23,8 +23,6 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.8",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
@@ -35,8 +33,8 @@ classifiers = [
 
 # --- Dependencies ---
 dependencies = [
-    "numpy>=1.21",
-    "numba"
+    "numpy>=2.0",
+    "numba>=0.60"
 ]
 
 # --- Optional Dependencies (Extras) ---
@@ -47,5 +45,5 @@ dev = ["pytest"]
 [project.urls]
 Homepage = "https://polysolve.jono-rams.work"
 Documentation = "https://polysolve.jono-rams.work/docs"
-Repository  = "https://github.com/jono-rams/PolySolve"
+Repository = "https://github.com/jono-rams/PolySolve"
 "Bug Tracker" = "https://github.com/jono-rams/PolySolve/issues"