ICU-22874 Update ICU4C to use a current version of the autotools

[roubert]

Checklist

• Required: Issue filed: https://unicode-org.atlassian.net/browse/ICU-22874
• Required: The PR title must be prefixed with a JIRA Issue number.
• Required: The PR description must include the link to the Jira Issue, for example by completing the URL in the first checklist item
• Required: Each commit message must be prefixed with a JIRA Issue number.
• Issue accepted (done by Technical Committee after discussion)
• Tests included, if applicable
• API docs and/or User Guide docs changed or added, if applicable

ALLOW_MANY_COMMITS=true

[markusicu]

Thank you!
@roubert or @srl295 do we need to update the relevant LICENSE file sections for this new version?
https://github.com/unicode-org/icu/blob/main/LICENSE#L464-L525

@yumaoka FYI

[roubert]

@roubert or @srl295 do we need to update the relevant LICENSE file sections for this new version?

I can't imagine why that would be necessary (but on the other hand, I'm generally not very good at imagining such stuff).

[markusicu]

@roubert or @srl295 do we need to update the relevant LICENSE file sections for this new version?

I can't imagine why that would be necessary (but on the other hand, I'm generally not very good at imagining such stuff).

Well, the license texts should be in sync between files that have special license and our collective LICENSE file.

I just checked, and only one character changed in the license text in one of these files

• ICU-22874 sync config.guess license #3182

[roubert]

I just checked, and only one character changed in the license text in one of these files

• ICU-22874 sync config.guess license #3182

OK, changing that semicolon to a comma is definitely something that I could never have imagined that it would matter,

[markusicu]

It probably doesn't matter, but it's good to be in sync.