ICU-22837 Update config.guess config.sub for WASI support

[kateinoigakukun]

WASI targets (e.g. wasm32-unknown-wasi) are not detected with the current config.guess/config.sub, which date back to 2017.

The latest config.guess and config.sub in https://git.savannah.gnu.org/cgit/config.git have WASI target support, so we need to update them to prepare for the upcoming WASI support patch set.

These files are copied from:

• https://git.savannah.gnu.org/cgit/config.git/plain/config.guess
• https://git.savannah.gnu.org/cgit/config.git/plain/config.sub

Checklist

• Required: Issue filed: https://unicode-org.atlassian.net/browse/ICU-22837
• 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

[markusicu]

@srl295 please compare with upstream; will configure need to be regenerated?