[SPDK] SPDK release cadence

Hi,

The SPDK project has historically done quarterly releases, with an LTS release every January.  To reduce the overhead burden of the release process, the SPDK project is planning to move to a 3x per year release cadence (every 4 months), starting with the next release – 22.05 in May 2022.  SPDK would continue with an annual LTS release every January.

Note that this would also align SPDK with the newly adopted 3x per year DPDK release cadence.  SPDK and DPDK releases will now alternate every two months (SPDK in January, DPDK in March, SPDK in May, etc.)

If you have any questions or concerns about the new release cadence, please let the core maintainers know, either here on the mailing list, or in one of the SPDK Slack channels.

Thanks,

Jim Harris (on behalf of the SPDK core maintainers)