Add python 3.14 testing (#589)

Author: braingram

.github/workflows/tests.yml

@@ -24,24 +24,18 @@ jobs:
           coverage: codecov
         - linux: py311
         - linux: py312
-        - linux: py313-cov
+        - linux: py313
+        - linux: py314-cov
           coverage: codecov
-        - macos: py313
+        - macos: py314
         - linux: py313-withromancal-cov
           coverage: codecov
-        # `tox` does not currently respect `requires-python` versions when creating testing environments;
-        # if this breaks, add an upper pin to `requires-python` and revert this py3 to the latest working version
-        # - linux: py3-cov
-        #   coverage: codecov
-        # - macos: py3
-        # - linux: py3-withromancal-cov
-        #   coverage: codecov
 
   test_upstream:
     uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@28e947497bed4d6ec3fa1d66d198e95a1d17bc63  # v2.2.1
     with:
       envs: |
-        - linux: py313-rad
+        - linux: py314-rad
 
   environment:
     runs-on: ubuntu-latest