deps: update icu to 78.1

[nodejs-github-bot]

This is an automated update of icu to 78.1.

[nodejs-github-bot]

Review requested:

• @nodejs/security-wg

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/69987/

[targos]

/cc @nodejs/i18n-api This output change is weird: https://ci.nodejs.org/job/node-test-commit-linuxone/nodes=rhel9-s390x/52175/testReport/junit/(root)/parallel/test_datetime_change_notify/

  AssertionError [ERR_ASSERTION]: The input did not match the regular expression /Irish Standard Time|Greenwich Mean Time/. Input:

  '11/1/2025, 10:49:12 AM GMT+00:00'

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.54%. Comparing base (24bebd0) to head (5afe4cd).

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #60523      +/-   ##
==========================================
- Coverage   88.55%   88.54%   -0.01%     
==========================================
  Files         704      704              
  Lines      207843   207843              
  Branches    40038    40043       +5     
==========================================
- Hits       184046   184034      -12     
+ Misses      15844    15841       -3     
- Partials     7953     7968      +15     

see 32 files with indirect coverage changes

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[richardlau]

/cc @nodejs/i18n-api This output change is weird: https://ci.nodejs.org/job/node-test-commit-linuxone/nodes=rhel9-s390x/52175/testReport/junit/(root)/parallel/test_datetime_change_notify/

  AssertionError [ERR_ASSERTION]: The input did not match the regular expression /Irish Standard Time|Greenwich Mean Time/. Input:

  '11/1/2025, 10:49:12 AM GMT+00:00'

FWIW it looks like a change when DST is not in effect (no longer outputs Greenwich Mean time):

> process.env.TZ='Europe/Dublin'
'Europe/Dublin'
> new Date('2025/10/01').toLocaleString('en-US', { timeZoneName: 'long' })
'10/1/2025, 12:00:00 AM Irish Standard Time'
> new Date('2025/11/01').toLocaleString('en-US', { timeZoneName: 'long' })
'11/1/2025, 12:00:00 AM GMT+00:00'
>