build-system: Introduce @* macro for lazy module resolution.

* guix/build-system.scm (@*): New macro for runtime module resolution.
* guix/build-system/agda.scm (default-agda): Use @* instead of
resolve-interface and module-ref.
* guix/build-system/android-ndk.scm (default-android-build,
default-android-googletest): Likewise.
* guix/build-system/ant.scm (default-jdk, default-ant, default-zip):
Likewise.
* guix/build-system/cargo.scm (default-rust): Likewise.
* guix/build-system/chicken.scm (default-chicken): Likewise.
* guix/build-system/composer.scm (default-php,
default-composer-classloader): Likewise.
* guix/build-system/dub.scm (default-ldc, default-dub,
default-pkg-config, default-ld-gold-wrapper): Likewise.
* guix/build-system/elm.scm (default-elm, default-elm-core,
default-elm-json): Likewise.
* guix/build-system/emacs.scm (default-emacs): Likewise.
* guix/build-system/glib-or-gtk.scm (default-glib): Likewise.
* guix/build-system/go.scm (default-go, default-gccgo, make-go-std):
Likewise.
* guix/build-system/haskell.scm (default-haskell): Likewise.
* guix/build-system/julia.scm (default-julia): Likewise.
* guix/build-system/linux-module.scm (default-linux): Likewise.
* guix/build-system/luanti.scm (default-optipng, default-luanti,
default-luanti-game, default-xvfb-run): Likewise. Remove otherwise
unused individual plugin accessor functions.
* guix/build-system/maven.scm (default-maven, default-jdk,
default-maven-plugins): Likewise. Remove otherwise unused individual
plugin accessor functions.
* guix/build-system/meson.scm (default-ninja, default-meson):
Likewise.
* guix/build-system/minify.scm (default-esbuild): Use @* instead of
resolve-interface and module-ref.
* guix/build-system/mix.scm (default-elixir-hex,
default-rebar3, default-elixir): Likewise.
* guix/build-system/node.scm (default-node): Likewise.
* guix/build-system/ocaml.scm (default-ocaml, default-findlib,
default-dune-build-system, default-ocaml4.07,
default-ocaml4.07-findlib ,default-ocaml4.07-dune, default-ocaml4.09,
default-ocaml4.09-findlib, default-ocaml4.09-dune, default-ocaml5.0,
default-ocaml5.0-findlib, default-ocaml5.0-dune): Likewise.
* guix/build-system/perl.scm (default-perl): Likewise.
* guix/build-system/pyproject.scm (default-python): Likewise.
* guix/build-system/qt.scm (default-qtbase): Likewise.
* guix/build-system/r.scm (default-r): Likewise.
* guix/build-system/rakudo.scm (default-rakudo, default-prove6,
default-zef): Likewise.
* guix/build-system/rebar.scm (default-rebar3, default-erlang):
Likewise.
* guix/build-system/renpy.scm (default-renpy): Likewise.
* guix/build-system/ruby.scm (default-ruby): Likewise.
* guix/build-system/scons.scm (default-scons): Likewise.
* guix/build-system/texlive.scm (default-texlive-bin,
texlive-latex-bin): Likewise.
* guix/build-system/tree-sitter.scm (default-guile-json,
default-node, default-tree-sitter, default-tree-sitter-cli): Likewise.
* guix/build-system/vim.scm (default-vim, default-neovim): Likewise.
* guix/build-system/zig.scm (default-zig): Likewise.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

guix/build-system/vim.scm

@@ -45,15 +45,12 @@
     ,@%copy-build-system-modules))
 
 (define (default-vim)
-  "Return the default Vim package."
-  ;; Lazily resolve the binding to avoid a circular dependency.
-  (let ((vim (resolve-interface '(gnu packages vim))))
-    (module-ref vim 'vim)))
+  "Return the default Vim package, resolved lazily."
+  (@* (gnu packages vim) vim))
 
 (define (default-neovim)
-  "Return the default Neovim package."
-  (let ((vim (resolve-interface '(gnu packages vim))))
-    (module-ref vim 'neovim)))
+  "Return the default Neovim package, resolved lazily."
+  (@* (gnu packages vim) neovim))
 
 (define* (lower name
                 #:key source