please.sh build-mingw-w64-git: configure the editor explicitly (#685)

For historical reasons, Git configures `vi` as the default editor, and
the Git for Windows project followed suite.

As part of collaborating more closely with MSYS2, the `mingw-w64-git`
package definition of Git for Windows is being synchronized between both
projects. And MSYS2 has a different default editor, also for historical
reasons: `nano`.

As a consequence, https://github.com/msys/MINGW-packages/aae0c9d1c8
(git: default to nano instead of vim (#28202), 2026-03-01) changed the
package definition to build with `nano` as Git's default editor.

This hard-coded value would have prevented Git for Windows to maintain
_its_ default, and for that reason, the MSYS2 project added another
commit, https://github.com/msys/MINGW-packages/d3ff7a1ec7 (git: allow
_DEFAULT_EDITOR override, 2026-03-11), to allow Git for Windows to
override that default.

This is what we do here: override the default, by setting
`_DEFAULT_EDITOR` to `vim`.

Technically, this is a slight deviation from the previous default, which
was `vi`. But the package definition uses this variable for two things:
to tell Git's build process what the default editor is, and to add the
corresponding package. But there is no `vi` package, only [a `vim`
one](https://github.com/msys2/MSYS2-packages/blob/HEAD/vim/PKGBUILD).

Author: dscho

please.sh

@@ -898,7 +898,7 @@ build_mingw_w64_git () { # [--only-i686] [--only-x86_64] [--only-aarch64] [--ski
 		export SIGNTOOL="git ${d:+--git-dir="$d"} signtool"
 	 fi &&
 	 cd ${git_src_dir%/src/git}/ &&
-	 MAKEFLAGS=${MAKEFLAGS:--j$(nproc)} makepkg-mingw $maybe_sync $force -p PKGBUILD.$tag &&
+	 _DEFAULT_EDITOR=vim MAKEFLAGS=${MAKEFLAGS:--j$(nproc)} makepkg-mingw $maybe_sync $force -p PKGBUILD.$tag &&
 	 if test -n "$src_pkg"
 	 then
 		git --git-dir src/git/.git archive --prefix git/ -o git-$tag.tar.gz $tag &&