minor: bump minimum python to 3.9

Author: mrava87

.github/workflows/build.yaml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         platform: [ ubuntu-latest, macos-13 ]
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
 
     runs-on: ${{ matrix.platform }}
     steps:

docs/source/installation.rst

@@ -9,7 +9,7 @@ The PyLops project strives to create a library that is easy to install in
 any environment and has a very limited number of dependencies.
 Required dependencies are limited to:
 
-* Python 3.8 or greater
+* Python 3.9 or greater
 * `NumPy <http://www.numpy.org>`_
 * `SciPy <http://www.scipy.org/scipylib/index.html>`_