Fix FTBFS

... (rhbz#2244833, rhbz#2340163)

With apologies to python-sig members ;(

(cherry picked from commit 23a5f53cc0)

flow-tools.spec

@@ -35,7 +35,7 @@ BuildRequires: bison
 BuildRequires: flex
 BuildRequires: doxygen
 %if 0%{?fedora} >= 31
-BuildRequires: /usr/bin/2to3
+BuildRequires: python3.12
 %endif
 Requires(pre): shadow-utils
 BuildRequires: systemd-rpm-macros
@@ -111,7 +111,7 @@ This package contains additional documentation, such as man pages in html format
 # Remove /bin/env deps
 %if 0%{?fedora} >= 31
 sed -i '1s|^#!.*python|#!/usr/bin/python3|' bin/flow*
-2to3 --write --nobackups bin/flow*
+python3.12 -m lib2to3 --write --nobackups bin/flow*
 %else
 sed -i '1s|^#!.*python|#!/usr/bin/python2|' bin/flow*
 %endif
@@ -120,6 +120,7 @@ sed -i '1s|^#!.*perl|#!/usr/bin/perl|' utils/*
 sed -i s/my_init/mysql_init/g configure
 
 %build
+export CFLAGS="$CFLAGS -std=gnu17"
 %configure \
   --localstatedir=%{_localstatedir}/%{name} \
   --sysconfdir=%{_sysconfdir}/%{name} \