Based on https://anonscm.debian.org/viewvc/pkg-java/trunk/libxerces2-java/debian/patches/03_bootclasspath.patch?revision=14509, adopted for guix

--- xerces-2_11_0/build.xml.orig	2010-11-26 21:42:11.000000000 +0100
+++ xerces-2_11_0/build.xml	2017-03-28 14:04:41.946606996 +0200
@@ -290,13 +290,14 @@
            destdir="${build.dest}"
            source="${javac.source}"
            target="${javac.target}"
-           classpath="${build.dir}/classes:${tools.dir}/${jar.apis}:${tools.dir}/${jar.resolver}:${tools.dir}/${jar.serializer}"
+           classpath="${build.dir}/classes:${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
            debug="${debug}" nowarn="true"
            debuglevel="${debuglevel}"
            deprecation="${deprecation}"
            optimize="${optimize}"
            includeAntRuntime="false"
-           includeJavaRuntime="false"
+           includeJavaRuntime="true"
+           bootclasspath="${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
            excludes="org/xml/sax/** 
                 javax/xml/**
                 org/w3c/dom/*
@@ -1451,13 +1452,14 @@
                destdir="${build.dest}"
                source="${javac.source}"
                target="${javac.target}"
-               classpath="${build.dir}/classes:${tools.dir}/${jar.apis}:${tools.dir}/${jar.resolver}:${tools.dir}/${jar.serializer}"
+               classpath="${build.dir}/classes:${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
                debug="${debug}"
                debuglevel="${debuglevel}"
                deprecation="${deprecation}"
                optimize="${optimize}"
                includeAntRuntime="false"
-               includeJavaRuntime="false"
+               includeJavaRuntime="true"
+               bootclasspath="${jar.jaxp}:${jar.apis-ext}:${jar.resolver}"
                excludes="org/xml/sax/** 
                     javax/xml/**
                     org/w3c/dom/*
log/?id=8c9d95a47cbf1ec77844a6050873aaed273e2a76'>root</a>/<a href='/guix/log/etc?id=8c9d95a47cbf1ec77844a6050873aaed273e2a76'>etc</a>/<a href='/guix/log/etc/teams?id=8c9d95a47cbf1ec77844a6050873aaed273e2a76'>teams</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/teams?id=8c9d95a47cbf1ec77844a6050873aaed273e2a76&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-03-19 03:40:08 -0400'>2024-03-19</span></td><td><a href='/guix/commit/etc/teams?id=a8ba2f3507d03ec77506a03bf84d62f9cb439f8e'>teams: qt: Remove erroneous comment at top of scripts.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/teams/qt/common.scm: Remove erroneous comment.
* etc/teams/qt/qt-manifest.scm: Likewise.
* etc/teams/qt/qt5-manifest.scm: Likewise.

Change-Id: I87a0ea669caa0ba5049b48a4f04fda58518c3f05
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2024-01-04 12:31:45 +0200'>2024-01-04</span></td><td><a href='/guix/commit/etc/teams?id=8b559b37eafbf51fe4a602c091754a38b8ad28f7'>etc: Add rust-team manifest.</a><span class='msg-avail'>...<span class='msg-tooltip'>Change-Id: Ie43bd4a88d35270dcac7baaabeafbcc3a755db1e
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2023-08-22 12:32:20 -0400'>2023-08-22</span></td><td><a href='/guix/commit/etc/teams?id=0b994bb9b10b381376f1dfd8bd2bc9173ede2a66'>etc: Add Qt manifests for Qt maintenance.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/teams/qt/common.scm: New file.
* etc/teams/qt/qt-manifest.scm: Likewise.
* etc/teams/qt/qt5-manifest.scm: Likewise.
</span></span></td><td>Maxim Cournoyer</td></tr>