fixup! TO-DROP: build and test on Windows/ARM64

D'oh. Also need to use the aarch64 flavor of the Git SDK for the
tests...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

.github/workflows/main.yml

@@ -115,6 +115,8 @@ jobs:
       shell: bash
       run: tar xf artifacts.tar.gz && tar xf tracked.tar.gz
     - uses: git-for-windows/setup-git-for-windows-sdk@v1
+      with:
+        architecture: aarch64
     - name: test
       shell: bash
       run: . /etc/profile && ci/run-test-slice.sh ${{matrix.nr}} 10