Revert "Update ICU to 71-1 (#32879)"

[harryterkelsen]

This reverts commit 61124ef.

This roll was causing code size issued in Fuchsia.

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[flutter-dashboard]

It looks like this pull request may not have tests. Please make sure to add tests before merging. If you need an exemption to this rule, contact Hixie on the #hackers channel in Chat (don't just cc him here, he won't see it! He's on Discord!).

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[ditman]

Looks good, it's odd that the licenses are not reverting "cleanly" to the same hash or something (I guess there were other modifications to the file in between?)