Because of the way git works, you can pull from gitlab using a git client (either git itself on the command line, or one with a GUI) and push to github.
I don't know if that actually covers your situation well enough, but it's at least some way you can make it work.
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Because of the way git works, you can pull from gitlab using a git client (either git itself on the command line, or one with a GUI) and push to github.
I don't know if that actually covers your situation well enough, but it's at least some way you can make it work.