Reduce and conditionalize BuildRequires

- bzip2 is not used directly, only via bzip2-devel
- tar is not used directly either, %autosetup uses rpmuncompress
- desktop-file-utils is only used to install idle desktop file with main_python
- libappstream-glib is only used to validate idle appdata file with main_python
- /usr/sbin/ifconfig is no longer needed for test_uuid
- gcc-c++, glibc-all-langpacks, tzdata are only used in tests
  (although something pulls in tzdata even with bootstrap without tests, so this one is hard to verify)
- gmp-devel in not needed since Python 2.4 (mpz module was removed)
- libGL-devel appears unused (and hard to find why it ever was needed)

Courtesy of https://github.com/mkoncek/unbreq

python3.13.spec

@@ -273,28 +273,34 @@ Obsoletes: python%{pybasever}%{?1:-%{1}}\
 
 BuildRequires: autoconf
 BuildRequires: bluez-libs-devel
-BuildRequires: bzip2
 BuildRequires: bzip2-devel
+%if %{with main_python}
 BuildRequires: desktop-file-utils
+%endif
 # See the runtime requirement in the -libs subpackage
 BuildRequires: expat-devel >= 2.6
 
 BuildRequires: findutils
+BuildRequires: gcc
+%if %{with tests}
 BuildRequires: gcc-c++
+%endif
 %if %{with gdbm}
 BuildRequires: gdbm-devel
 %endif
 BuildRequires: git-core
+%if %{with tests}
 BuildRequires: glibc-all-langpacks
+%endif
 BuildRequires: glibc-devel
-BuildRequires: gmp-devel
 BuildRequires: gnupg2
+%if %{with main_python}
 BuildRequires: libappstream-glib
+%endif
 %if %{undefined rhel}
 BuildRequires: libb2-devel
 %endif
 BuildRequires: libffi-devel
-BuildRequires: libGL-devel
 BuildRequires: libuuid-devel
 BuildRequires: libX11-devel
 BuildRequires: make
@@ -307,12 +313,15 @@ BuildRequires: python-rpm-macros
 BuildRequires: readline-devel
 BuildRequires: redhat-rpm-config >= 127
 BuildRequires: sqlite-devel
+%if %{with tests}
 BuildRequires: gdb
+%endif
 
-BuildRequires: tar
 BuildRequires: tcl-devel
 BuildRequires: tk-devel
+%if %{with tests}
 BuildRequires: tzdata
+%endif
 
 %if %{with jit}
 BuildRequires: clang(major) = 18
@@ -328,9 +337,6 @@ BuildRequires: zlib-devel
 
 BuildRequires: /usr/bin/dtrace
 
-# workaround http://bugs.python.org/issue19804 (test_uuid requires ifconfig)
-BuildRequires: /usr/sbin/ifconfig
-
 %if %{with rpmwheels}
 # Python 3.12 removed the deprecated imp module,
 # the first compatible version of pip is 23.1.2.