Glitch currently doesn't support authoring GitHub Actions inside the editor and will not commit workflow files when you export a project to GitHub.
You can still work on projects that use Actions as long as you don't attempt to create or edit the Actions code inside Glitch.
Author your Actions outside Glitch
The recommended location for GitHub Actions code is in a YAML file inside the .github/workflows directory.
Avoid creating GitHub Actions code inside the Glitch editor, because your project will fail to export back to GitHub while these are present. If created the workflows folder in Glitch, remove it before you attempt an export.
You can import a repo that includes GitHub Actions code in a .github/workflows/*.yml into a Glitch project and imports / exports should continue to work as long as you don't attempt to edit the Actions code inside the Glitch editor.
The file won't appear in your project directory in the Glitch editor–you also won't be able to edit it on the terminal or imports / exports will stop working. You can edit other files in your project as usual and export to GitHub, where the Actions code will still be present in the repo and should trigger runs as normal.