build(deps): bump actions/setup-go from 5 to 6

[dscho]

(Originally opened at git-for-windows#5811)

Bumps actions/setup-go from 5 to 6.

• Release notes
• Commits

What's Changed in actions/setup-go@v6

Breaking Changes

• Improve toolchain handling to ensure more reliable and consistent toolchain selection and management by @matthewhughes934 in #460
• Upgrade Nodejs runtime from node20 to node 24 by @salmanmkc in #624

Make sure your runner is on version v2.327.1 or later to ensure compatibility with this release. See Release Notes

[github-actions]

Warnings found by git-po-helper in workflow #1071:

INFO no missing blobs of po/* in partial clone    
------------------------------------------------------------------------------
WARNING commit 406e227: author (dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>) and committer (Johannes Schindelin <[email protected]>) are different 
INFO checking commits: 1 passed.                  
------------------------------------------------------------------------------
INFO downloading pot file from https://github.com/git-l10n/pot-changes/raw/pot/master/po/git.pot 

[jiangxin]

Hi @dscho ,

Thank you for this fix. It's better to send this patch to the Git mailing list, so it won't have to wait until the next l10n window opens and can be merged sooner.

[jiangxin]

I followed your changes and upgraded the GitHub Actions version for the git-l10n/git-po-helper project, and GitHub Actions is working fine.

• git-l10n/git-po-helper@7a86617

[dscho]

Okay, then, moving to gitgitgadget#1975.

[dscho]

I followed your changes and upgraded the GitHub Actions version for the git-l10n/git-po-helper project, and GitHub Actions is working fine.

* [git-l10n/git-po-helper@7a86617](https://github.com/git-l10n/git-po-helper/commit/7a866175d3196d63431f3f7caaaf8ef7c1c5b101)

Oops. Okay, then. I wonder why you couldn't simply merge this PR, though. Seems like I wasted my time.

[jiangxin]

I followed your changes and upgraded the GitHub Actions version for the git-l10n/git-po-helper project, and GitHub Actions is working fine.

* [git-l10n/git-po-helper@7a86617](https://github.com/git-l10n/git-po-helper/commit/7a866175d3196d63431f3f7caaaf8ef7c1c5b101)

Oops. Okay, then. I wonder why you couldn't simply merge this PR, though. Seems like I wasted my time.

I can only merge changes for files in the "po/" directory. I will send your patch to git list, let Junio to review and merge.