RFR: Updated Code Owners for JDK 20

Wed May 17 15:47:18 UTC 2023

This should be done after each release to make sure the list is kept up to date.

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Commit messages:
 - Updated Code Owners for JDK 20

Changes: https://git.openjdk.org/guide/pull/103/files
 Webrev: https://webrevs.openjdk.org/?repo=guide&pr=103&range=00
  Stats: 136 lines in 1 file changed: 62 ins; 12 del; 62 mod
  Patch: https://git.openjdk.org/guide/pull/103.diff
  Fetch: git fetch https://git.openjdk.org/guide.git pull/103/head:pull/103

PR: https://git.openjdk.org/guide/pull/103