.github/zephyr: de-hardcode the remote name in the Windows build too

Fixes commit 4bc6488 (".github/zephyr: de-hardcode the name of the
zephyr remote")

(Yay for duplication)

Signed-off-by: Marc Herbert <marc.herbert@intel.com>

.github/workflows/zephyr.yml

@@ -308,7 +308,7 @@ jobs:
  # Get some tags to fix `git describe`, see build-linux comments above.
  cd zephyr
  $_rev = "$(git rev-parse HEAD)"
- git fetch --filter=tree:0 zephyrproject "${_rev}:_branch_placeholder"
+ git fetch --filter=tree:0 "$(west list -f '{url}' zephyr)" "${_rev}:_branch_placeholder"
  git branch -D _branch_placeholder