pgsql: Update copyright for 2024

Update copyright for 2024

Reported-by: Michael Paquier

Discussion: /messages/by-id/ZZKTDPxBBMt3C0J9@paquier.xyz

Backpatch-through: 12

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/49fa18390cfbd03956a4820910777c3d6585d5a7

Modified Files
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COPYRIGHT | 2 +-
doc/src/sgml/legal.sgml | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)