pkgdep: Add python3-devel installation for sles

Add installation of python3-devel to pkgdep/sles.sh to satisfy
build-time requirements specified in spdk.spec. Without this package,
builds on SLES fail due to missing Python headers and development tools
required by SPDK.

Change-Id: Ifc23eb1bab1e0b1d312b8f917b7a564343f4d32b
Signed-off-by: Przemyslaw Wielgo <przemyslaw.wielgo@dell.com>
Reviewed-on: https://review.spdk.io/c/spdk/spdk/+/26464


Reviewed-by: Jim Harris <jim.harris@nvidia.com>
Reviewed-by: Boris Glimcher <Boris.Glimcher@emc.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Michal Berger <michal.berger@nutanix.com>
Tested-by: SPDK Automated Test System <spdkbot@gmail.com>
Reviewed-by: Karol Latecki <karol.latecki@nutanix.com>
Reviewed-by: Ben Walker <ben@nvidia.com>