l10n: bump actions/setup-go from 5 to 6

[Originally opened at git-for-windows#5811]

Bumps [actions/setup-go](https://github.com/actions/setup-go)
from 5 to 6.
- [Release notes](https://github.com/actions/setup-go/releases)
- [Commits](actions/setup-go@v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-go
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

  Original-author: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Signed-off-by: dependabot[bot] <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

.github/workflows/l10n.yml

@@ -63,7 +63,7 @@ jobs:
             origin \
             ${{ github.ref }} \
             $args
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@v6
         with:
           go-version: '>=1.16'
           cache: false