ci-artifacts: build git/git again

In 1b7ec02 (ci-artifacts: revert to building git-for-windows/git for
now, 2025-04-15), I changed `git-sdk-arm64`'s `ci-artifacts` workflow so
that it builds git-for-windows/git instead of git/git. The reason was
that a lot of work had to be done first before building that branch in
`ci-artifacts` would succeed, which was upstreamed as
gitgitgadget/git#1904 (and which I expected to
take the usual loooong time to trickle down, but Junio seemed to be in a
good mood back then and it took only two weeks and two days).

Since this is all resolved now, let's switch back by reverting
1b7ec02.

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

Author: dscho

.github/workflows/ci-artifacts.yml

@@ -43,9 +43,9 @@ jobs:
         with:
           name: minimal-sdk
           path: artifacts/git-sdk-aarch64-minimal.tar.gz
-      - name: clone git-for-windows/git's `main`
-        run: git clone --depth=1 --branch main https://github.com/git-for-windows/git ..\git
-      - name: build current `main` of git-for-windows/git
+      - name: clone git.git's `master`
+        run: git clone --depth=1 --branch master https://github.com/git/git ..\git
+      - name: build current `master` of git.git
         shell: bash
         run: |
           set -x