rpm: switch to using python 3

Part of #5562

Author: ligurio

rpm/tarantool.spec

@@ -76,19 +76,16 @@ BuildRequires: libunwind-devel
 %endif
 
 # Set dependences for tests.
-# Do not install unused Python 3 packages which
-# is default since Fedora 31 and CentOS 8.
 %if (0%{?fedora} >= 31 || 0%{?rhel} >= 8)
-BuildRequires: python2 >= 2.7
-BuildRequires: python2-six >= 1.9.0
-BuildRequires: python2-gevent >= 1.0
-BuildRequires: python2-yaml >= 3.0.9
+BuildRequires: python3-six
+BuildRequires: python3-gevent
+BuildRequires: python3-yaml
 %else
 %if (0%{?rhel} != 6 || 0%{?sle_version} >= 1500)
-BuildRequires: python >= 2.7
-BuildRequires: python-six >= 1.9.0
-BuildRequires: python-gevent >= 1.0
-BuildRequires: python-yaml >= 3.0.9
+BuildRequires: python3
+BuildRequires: python-six
+BuildRequires: python-gevent
+BuildRequires: python-yaml
 %endif
 %endif