pgsql: Update time zone data files to tzdata release 2026e.

Update time zone data files to tzdata release 2026e.

Canada's Northwest Territories will move to permanent UTC-06 on
2026-11-01. For now, assume their TZ abbreviation will be CST from
that time forward. This affects only America/Inuvik as the rest of
the territory is covered by America/Edmonton, for which the
equivalent change was released in 2026c.

Manitoba (America/Winnipeg) will move to permanent UTC-05 on
2026-10-31. For now, assume their TZ abbreviation will be EST
from that time forward.

(Upstream notes that more changes may be needed soon if smaller
jurisdictions choose to break away from what these have done,
but for now the plan is wait-and-see.)

Historical corrections for Colombia, Iran, and Ireland.

The backward-compatibility zone names EST5EDT, CST6CDT, MST7MDT, and
PST8PDT now conform better to POSIX. For example, EST5EDT now always
uses the abbreviation "EST" for standard time (now always 5 hours
behind UTC) and "EDT" for daylight saving time, whereas it formerly
had different UT offsets before standard time was introduced and
sometimes used abbreviations like "LMT", "EWT" and "EPT", all contrary
to POSIX. Also, though not specified by POSIX these names now use US
federal rules rather than rules of specific places like New York,
reverting to 2024a behavior. This change affects only timestamps
before 1966-10-30 at 01:00 standard time.

Backpatch-through: 14

Branch
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REL_19_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/9e73b2095f5f9c74be0be4f62450e1503762129a

Modified Files
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src/timezone/data/tzdata.zi | 55 ++++++++++++++++++++++++++++++---------------
1 file changed, 37 insertions(+), 18 deletions(-)