fix: remove unused setting of git remote add gh-token in major and minor tag updating

[dlaehnemann]

We have been flagged about this by @coderabbitai in one of our repositories, and looking at this in more detail I agree with the analysis:
snakemake/snakemake-github-action#46 (comment)

Namely, the git remote gh-token that is added here, is not used anywhere. So unless this gets used implicitly, it should not be needed and should be omitted in both the CI and the suggestion in the README.md.

If this is indeed used implicitly in some way (for example to be able to delete and add tags in the repository), then it should always be adjusted to respective repository, right? In that case, I would suggest to revert the change in .github/workflows/release-please.yaml and instead change the line in the README.md to something like:

          git remote add gh-token "https://${{ secrets.GITHUB_TOKEN }}@github.com/<ORGANIZATION>/<REPOSITORY>.git"

And maybe also mention that this requires adjusting in the text before it. But in this way, the line will not run anyways and throw an error, alerting anybody copying it, that they need to adjust this.

All of this was originally added in #121 , so maybe @bcoe and/or @bharathkkb can quickly asses this?

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[dlaehnemann]

In the case where this line came up as flagged by @coderabbitai for us, we have confirmed that the tag updating works properly without this extra (unused) remote being set up.

@chingor13 is there anything else I can do to help get this pull request rolling and the question cleared up?