Bump minimum supported python version to 3.10

Bump oldest numpy

Trying to get numpy to install

Add MacOS 3.10 test

Update numpy pin here as well

Bump oldest supported scipy

Updated versions in contributing.rst

.github/workflows/ci_workflows.yml

@@ -37,20 +37,15 @@ jobs:
             python: '3.12'
             toxenv: py312-test
 
-          - name: Python 3.10
-            os: ubuntu-latest
+          - name: Python 3.10 (MacOS)
+            os: macos-latest
             python: '3.10'
             toxenv: py310-test
 
-          - name: Python 3.9
+          - name: Python 3.10 with oldest supported version of key dependencies
             os: ubuntu-latest
-            python: 3.9
-            toxenv: py39-test
-
-          - name: Python 3.8 with oldest supported version of key dependencies
-            os: ubuntu-20.04
-            python: 3.8
-            toxenv: py38-test-oldestdeps
+            python: '3.10'
+            toxenv: py310-test-oldestdeps
 
     steps:
     - name: Checkout code

CHANGES.rst

@@ -12,6 +12,8 @@ Bug Fixes
 Other Changes and Additions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+- Dropped support for python 3.9. [#1176]
+
 - ``utils.wcs_utils.refraction_index`` (and thus ``air_to_vac`` and ``vac_to_air``)
   now defaults to ``Morton2000`` as the method instead of ``Griesen2006``. [#1169]
 

docs/contributing.rst

@@ -107,7 +107,7 @@ Before you submit a pull request, check that it meets these guidelines:
 2. If the pull request adds functionality, the docs should be updated. Put
    your new functionality into a function with a docstring, and add the
    feature to the list in README.rst.
-3. The pull request should work for Python 3.9 - 3.11, and for PyPy. Check
+3. The pull request should work for Python 3.10 - 3.12, and for PyPy. Check
    that all required tests passed in the Github Actions CI section at the
    bottom of your pull request.
 

setup.cfg

@@ -14,9 +14,9 @@ github_project = astropy/specutils
 [options]
 zip_safe = False
 packages = find:
-python_requires = >=3.8
+python_requires = >=3.10
 install_requires =
-    numpy>=1.19
+    numpy>=1.24
     scipy>=1.3
     astropy>=5.1
     gwcs>=0.18

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py{38,39,310,311,312}-test{,-devdeps,-oldestdeps,-predeps}{,-cov,-external}
+    py{310,311,312}-test{,-devdeps,-oldestdeps,-predeps}{,-cov,-external}
     linkcheck
     codestyle
 isolated_build = true
@@ -38,8 +38,8 @@ description =
 deps =
     cov: pytest-cov
 
-    oldestdeps: numpy==1.19.*
-    oldestdeps: scipy==1.3.*
+    oldestdeps: numpy==1.24.4
+    oldestdeps: scipy==1.8.*
     oldestdeps: astropy==5.1.*
     oldestdeps: gwcs==0.18.*
     oldestdeps: asdf-astropy==0.3.*