Use python3-devel in bindep for rpm distros

python36-devel is not available in rpm distro's
like CentOS9-Stream or Fedora35.

Let's use python3-devel instead which is provided
in all these distro's instead of maintaining versioned
specific like:-
- python36-devel fo CentOS8-Stream
- python3.9-devel for CentOS9-Stream
- python3.10-devel for Fedora35

This is a partial cherry-pick of [1] as tox-py310 job is only
relevant for OpenStack Zed release.

[1] https://review.opendev.org/c/openstack/neutron/+/833101

Related-Bug: rhbz#2069099
Change-Id: I238e6b7f87d3e007d474dfffa515f7d9a348246b
(cherry picked from commit 52e302f0a3)

bindep.txt

@@ -1,7 +1,7 @@
 # This file contains runtime (non-python) dependencies
 # More info at: http://docs.openstack.org/infra/bindep/readme.html
 
-python36-devel [platform:rpm]
+python3-devel [platform:rpm]
 
 # tools/misc-sanity-checks.sh validates .po[t] files
 gettext [test]