Remove libtool archive (.la) files in Chapter 5 and 6

They are really harmful.  In Binutils pass 2, libstdc++.la caused the
building system to use host /usr/lib/libstdc++.so for gprofng.  We now
has disabled gprofng for pass 2, but the similar issue also exists in
GCC pass 2.  In a normal LFS build, the building system silently uses
/usr/lib/libstdc++.so (I guess it does not blow up simply because some
blind luck); in a real cross build (x86 -> ARM for example) the build
will fail.

Remove the .la files to fix this issue.  Instead of only modifying
clfs-ng, it makes more sense to apply the change for trunk: though
the build does not fail, using host library is still a contamination.

chapter01/changelog.xml

@@ -40,6 +40,16 @@
     appropriate for the entry or if needed the entire day's listitem.
     -->
 
+    <listitem>
+      <para>2022-08-18</para>
+      <itemizedlist>
+        <listitem>
+          <para>[xry111] - Remove libtool archive (.la) files in Chapter 5
+          and 6 because those files are harmful for cross compilation.</para>
+        </listitem>
+      </itemizedlist>
+    </listitem>
+
     <listitem>
       <para>2022-08-11</para>
       <itemizedlist>

chapter05/libstdc++.xml

@@ -121,6 +121,11 @@ cd       build</userinput></screen>
 
 <screen><userinput remap="install">make DESTDIR=$LFS install</userinput></screen>
 
+    <para>Remove the libtool archive files because they are harmful for
+    cross compilation:</para>
+
+<screen><userinput remap="install">rm -v $LFS/usr/lib/lib{stdc++,stdc++fs,supc++}.la</userinput></screen>
+
   </sect2>
 
   <sect2 role="content">

chapter06/binutils-pass2.xml

@@ -98,6 +98,11 @@ cd       build</userinput></screen>
 
 <screen><userinput remap="install">make DESTDIR=$LFS install</userinput></screen>
 
+    <para>Remove the libtool archive files because they are harmful for
+    cross compilation, and remove unnecessary static libraries:</para>
+
+<screen><userinput remap="install">rm -v $LFS/usr/lib/lib{bfd,ctf,ctf-nobfd,opcodes}.{a,la}</userinput></screen>
+
   </sect2>
 
   <sect2 role="content">

chapter06/file.xml

@@ -90,6 +90,11 @@ popd</userinput></screen>
 
 <screen><userinput remap="install">make DESTDIR=$LFS install</userinput></screen>
 
+    <para>Remove the libtool archive file because it is harmful for cross
+    compilation:</para>
+
+<screen><userinput remap="install">rm -v $LFS/usr/lib/libmagic.la</userinput></screen>
+
   </sect2>
 
   <sect2 role="content">

chapter06/xz.xml

@@ -59,6 +59,11 @@
 
 <screen><userinput remap="install">make DESTDIR=$LFS install</userinput></screen>
 
+    <para>Remove the libtool archive file because it is harmful for cross
+    compilation:</para>
+
+<screen><userinput remap="install">rm -v $LFS/usr/lib/liblzma.la</userinput></screen>
+
   </sect2>
 
   <sect2 role="content">