Avoid usage of PATH_MAX.

Taken from https://salsa.debian.org/freedesktop-team/fontconfig/-/blob/master/debian/patches/path_max.patch

Index: fontconfig-2.13.1/src/fccfg.c
===================================================================
--- fontconfig-2.13.1.orig/src/fccfg.c
+++ fontconfig-2.13.1/src/fccfg.c
@@ -2231,7 +2231,7 @@ FcConfigRealFilename (FcConfig		*config,
 
     if (n)
     {
-	FcChar8 buf[PATH_MAX];
+	FcChar8 buf[FC_PATH_MAX];
 	ssize_t len;
 
 	if (sysroot)
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<tr><td><span title='2023-04-21 16:16:38 +0200'>2023-04-21</span></td><td><a href='/guix/commit/tests/guix-package-net.sh?id=37dd69b44511dc73eb04bdebe8d82c9a0386338e'>tests: Fix checks for expected failures.</a><span class='msg-avail'>...<span class='msg-tooltip'>Addresses &lt;https://issues.guix.gnu.org/62406&gt;.

With 'set -e', a return status inverted with '!' does not cause the shell to
exit immediately.  Instead use '&amp;&amp; false' to indicate an expected failure.

* tests/guix-archive.sh, tests/guix-build-branch.sh, tests/guix-build.sh,
tests/guix-daemon.sh, tests/guix-download.sh,
tests/guix-environment-container.sh, tests/guix-environment.sh,
tests/guix-gc.sh, tests/guix-git-authenticate.sh, tests/guix-graph.sh,
tests/guix-hash.sh, tests/guix-home.sh, tests/guix-pack-relocatable.sh,
tests/guix-pack.sh, tests/guix-package-aliases.sh, tests/guix-package-net.sh,
tests/guix-package.sh, tests/guix-refresh.sh, tests/guix-shell.sh,
tests/guix-style.sh, tests/guix-system.sh: Replace uses of '! ...' with
'... &amp;&amp; false' or `test ! ...` as appropriate.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Eric Bavier</td></tr>