Remove docbook2X BuildRequire dependency as it is being deprecated

Resolves: RHEL-45561
docbook2X is being deprecated in RHEL10, and as the mutt is the only package that requires it, the config has been edited, so it is not being used anymore. The build process is not changed otherwise as the build still passes, and no changes in the log have been observed, which indicates that the package does not require it.

mutt.spec

@@ -20,7 +20,7 @@
 Summary: A text mode mail user agent
 Name: mutt
 Version: 2.2.12
-Release: 5%{?dist}
+Release: 6%{?dist}
 Epoch: 5
 # The entire source code is GPLv2+ except
 # pgpewrap.c setenv.c sha1.c wcwidth.c which are Public Domain
@@ -49,7 +49,6 @@ BuildRequires: ncurses-devel, gettext, automake
 BuildRequires: /usr/bin/xsltproc, docbook-style-xsl, perl-interpreter
 BuildRequires: perl-generators
 BuildRequires: lynx
-BuildRequires: docbook2X
 
 %if %{with hcache}
 %{?with_tokyocabinet:BuildRequires: tokyocabinet-devel}
@@ -220,6 +219,10 @@ ln -sf ./muttrc.5 %{buildroot}%{_mandir}/man5/muttrc.local.5
 
 
 %changelog
+* Sat Jun 22 2024 Ondrej Sloup <osloup@redhat.com> -  5:2.2.12-6
+- Remove docbook2X BuildRequire dependency as it is being deprecated
+- Resolves: RHEL-45561
+
 * Mon Jun 24 2024 Troy Dawson <tdawson@redhat.com> - 5:2.2.12-5
 - Bump release for June 2024 mass rebuild