v2021pre: Update release notes for v2021pre.1
A new point release has been published to include the linux kernel 5.10.x LTS version, which upstream didn't released in time for inclusion in v2021pre.0.
Task: T7573
A new point release has been published to include the linux kernel 5.10.x LTS version, which upstream didn't released in time for inclusion in v2021pre.0.
Task: T7573