Add a GitHub Action to replace Travis CI

[cclauss]

Travis CI is no longer free to open source so replace it with a GitHub Action to lint with ruff and test with pytest. Test results: https://github.com/cclauss/pybufrkit/actions

============================= test session starts ==============================
platform linux -- Python 3.11.2, pytest-7.2.2, pluggy-1.0.0
rootdir: /home/runner/work/pybufrkit/pybufrkit
collected 46 items

tests/test_Benchmark.py .                                                [  2%]
tests/test_Decoder.py .                                                  [  4%]
tests/test_Encoder.py .                                                  [  6%]
tests/test_Encoder_arguments.py .                                        [  8%]
tests/test_NodePathParser.py ..                                          [ 13%]
tests/test_Tables.py ..                                                  [ 17%]
tests/test_TemplateCompiler.py ..                                        [ 21%]
tests/test_TemplateData.py .                                             [ 23%]
tests/test_commands.py ..                                                [ 28%]
tests/test_dataquery.py ..........                                       [ 50%]
tests/test_generate_message.py ..                                        [ 54%]
tests/test_mdquery.py .........                                          [ 73%]
tests/test_nodepath.py .                                                 [ 76%]
tests/test_prepbufr.py .                                                 [ 78%]
tests/test_script.py ......                                              [ 91%]
tests/test_tablespreparer.py s                                           [ 93%]
tests/test_utils.py ...                                                  [100%]

======================== 45 passed, 1 skipped in 25.43s ========================

[ywangd]

Thanks for the PR. Somehow I missed the notification. Sorry for the delay. While I'd like to test it with more python versions and variants, it seems to be a good start to replace the non-functional travis CI.

[cclauss]

Thanks but I have been contributing to the dev branch as instructed but the branches have diverged and need to be unified so at least one works with the new version of Pythonista.

[cclauss]

Oops… This is not staSH