Two weeks until JDK 21 rampdown 1 start on June 8, 2023

[Joseph D. Darcy]

Hello,

Per the JDK 21 schedule (https://openjdk.org/projects/jdk/21/), the 
rampdown 1 phase of JDK 21 starts on June 8, 2023, two weeks from today.

Given the latency expected in the CSR review of large projects, no 
additional large projects, including JEPs, that have not already begun 
the CSR process for JDK 21 should expect to complete CSR review by the 
start of rampdown 1.

-Joe
CSR Lead