remove-packages-from-pacman-repository: fix GPG step

When I tried to run the workflow, it failed:

  gpg: directory '/d/a/_temp/home/.gnupg' created
  gpg: error running '/usr/bin/dirmngr': probably not installed
  gpg: failed to start dirmngr '/usr/bin/dirmngr': Configuration error
  gpg: can't connect to the dirmngr: Configuration error
  gpg: keyserver receive failed: No dirmngr

For full details, see
https://github.com/git-for-windows/git-for-windows-automation/actions/runs/13433913836/job/37531770052#step:6:18

The reason is obviously that the `dirmngr.exe` executable is not part of
the Git for Windows SDK `makepkg-git` flavor.

So let's use the `build-installers` flavor instead; This succeeds in
importing the GPG keys.

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

Author: dscho

.github/workflows/remove-packages-from-pacman-repository.yml

@@ -33,9 +33,7 @@ jobs:
       - name: Download Git for Windows SDK
         uses: git-for-windows/setup-git-for-windows-sdk@v1
         with:
-          flavor: makepkg-git
-          architecture: x86_64
-          msys: true
+          flavor: build-installers
 
       - name: Clone build-extra
         shell: bash