remove python 3.9 support/tests

.github/workflows/build.yml

@@ -110,7 +110,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
     runs-on: ${{ matrix.os }}
     steps:
       - name: Check out mitiq

CONTRIBUTING.md

@@ -12,7 +12,7 @@ The rest of this document describes the technical details of getting set up to d
 
 ## Development environment
 
-1. Ensure you have python 3.9 or greater installed. If not, you can find the downloads [here](https://www.python.org/downloads/).
+1. Ensure you have python 3.10 or greater installed. If not, you can find the downloads [here](https://www.python.org/downloads/).
 2. Set up a virtual environment to isolate dependencies. This can be done with many different tools including [Virtualenv](https://virtualenv.pypa.io/en/latest/), [Pipenv](https://pypi.org/project/pipenv/), [Poetry](https://python-poetry.org/), and [Anaconda](https://www.anaconda.com/download). In what follows we will use Anaconda, but if you're familiar with other tools feel free to use those.
 3. Set up a local version of the [Mitiq repository](https://github.com/unitaryfund/mitiq). To do this you will need to use `git` which is a version control system. If you're unfamiliar, check out the [docs](https://git-scm.com/), and learn about what the typical [`git` workflow](https://www.asmeurer.com/git-workflow/) looks like.
 4. Inside the Mitiq repository (`cd mitiq`), activate a virtual environment. With conda this is done using the following command.

requirements/requirements-pennylane.txt

@@ -1,4 +1,2 @@
 pennylane-qiskit~=0.36.0
-pennylane~=0.36.0
-# TODO: Remove qiskit-ibm-provider when upgrading qiskit-ibm-runtime in requirements-qiskit
-qiskit-ibm-provider~=0.11.0; python_version == '3.9'
+pennylane~=0.36.0

setup.py

@@ -67,7 +67,7 @@ def load_requirements(filename):
         "Documentation": "https://mitiq.readthedocs.io/en/stable/",
         "Source": "https://github.com/unitaryfund/mitiq/",
     },
-    python_requires=">=3.9,<3.13",
+    python_requires=">=3.10,<3.13",
 )
 
 # restore _version.py to its previous state