raise minimum required Python version to 3.8

This patch raises the minimum required Python version to 3.8 and removes
version 3.7 from the testing grid, which is end-of-lifed as of June 27, 2023.

.github/workflows/test.yaml

@@ -45,7 +45,6 @@ jobs:
           - {name: "baseline", os: ubuntu-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
           - {name: "windows", os: windows-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
           - {name: "macos", os: macos-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
-          - {name: "python 3.7", os: ubuntu-latest, python-version: "3.7", matrix-backend: numpy, nprocs: 1}
           - {name: "python 3.8", os: ubuntu-latest, python-version: "3.8", matrix-backend: numpy, nprocs: 1}
           - {name: "python 3.9", os: ubuntu-latest, python-version: "3.9", matrix-backend: numpy, nprocs: 1}
           - {name: "scipy matrix", os: ubuntu-latest, python-version: "3.10", matrix-backend: scipy, nprocs: 1}
@@ -54,7 +53,7 @@ jobs:
           - {name: "mkl windows", os: windows-latest, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
           - {name: "mkl macos", os: macos-latest, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
           - {name: "parallel", os: ubuntu-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 2}
-          - {name: "numpy 1.17", os: ubuntu-latest, python-version: "3.7", matrix-backend: numpy, nprocs: 1, numpy-version: ==1.17}
+          - {name: "numpy 1.17", os: ubuntu-latest, python-version: "3.8", matrix-backend: numpy, nprocs: 1, numpy-version: ==1.17.3}
           - {name: "tensorial", os: ubuntu-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1, tensorial: test}
       fail-fast: false
     env:

pyproject.toml

@@ -4,7 +4,7 @@ readme = "README.md"
 authors = [
     { name = "Evalf", email = "[email protected]" },
 ]
-requires-python = '~=3.7'
+requires-python = '~=3.8'
 dependencies = [
     "appdirs~=1.0",
     "bottombar~=2.0.2",