bug#65323: build failure on Alpine Linux

[Bruno Haible <bruno@clisp.org>]

A build of the current GNU Emacs sources on Alpine Linux 3.18 fails:

$ ./configure ... --without-all --without-x
$ make
...
make[2]: Leaving directory '/home/bruno/emacs/doc/misc'
./build-aux/install-sh -c -d ./info
(cd ./doc && \
 AWK='awk' ../build-aux/make-info-dir ../build-aux/dir_top emacs/emacs.texi lispintro/emacs-lisp-intro.texi lispref/elisp.texi misc/auth.texi misc/autotype.texi misc/bovine.texi misc/calc.texi misc/cc-mode.texi misc/cl.texi misc/dbus.texi misc/dired-x.texi misc/ebrowse.texi misc/ede.texi misc/ediff.texi misc/edt.texi misc/efaq.texi misc/eglot.texi misc/eieio.texi misc/emacs-gnutls.texi misc/emacs-mime.texi misc/epa.texi misc/erc.texi misc/ert.texi misc/eshell.texi misc/eudc.texi misc/eww.texi misc/flymake.texi misc/forms.texi misc/gnus.texi misc/htmlfontify.texi misc/idlwave.texi misc/ido.texi misc/info.texi misc/mairix-el.texi misc/message.texi misc/mh-e.texi misc/modus-themes.org misc/newsticker.texi misc/nxml-mode.texi misc/octave-mode.texi misc/org.org misc/pcl-cvs.texi misc/pgg.texi misc/rcirc.texi misc/reftex.texi misc/remember.texi misc/sasl.texi misc/sc.texi misc/semantic.texi misc/ses.texi misc/sieve.texi misc/smtpmail.texi misc/speedbar.texi misc/srecode.texi misc/todo-mode.texi misc/tramp.texi misc/transient.texi misc/url.texi misc/use-package.texi misc/vhdl-mode.texi misc/vip.texi misc/viper.texi misc/vtable.texi misc/widget.texi misc/wisent.texi misc/woman.texi \
) >info/dir.tmp && mv info/dir.tmp info/dir
awk: bad regex '@value{emacsname}': Invalid contents of {}
make[1]: *** [Makefile:1186: info/dir] Error 1
make[1]: Leaving directory '/home/bruno/emacs'

The problem is apparently the 'awk' program that ships with Alpine Linux:

$ awk --version
awk: unrecognized option: version
BusyBox v1.36.1 (2023-06-02 00:42:02 UTC) multi-call binary.

Usage: awk [OPTIONS] [AWK_PROGRAM] [FILE]...

        -v VAR=VAL      Set variable
        -F SEP          Use SEP as field separator
        -f FILE         Read program from FILE
        -e AWK_PROGRAM


It would be good if the INSTALL file would mention this requirement to
have a decent 'awk' program.

Bruno