pgsql: doc PG relnotes: add attribution for time zone data files items

doc PG relnotes: add attribution for time zone data files items

This is needed for a future script to add commit links; specifically we
need the closing parentheses of the attribution.

Backpatch-through: 12

Branch
------
REL_14_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/cc6d5bd91e9dbaeccf93f2c78de24ed80868a682

Modified Files
--------------
doc/src/sgml/release-14.sgml | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)