Update ICU

Rolling v8/third_party/icu: https://chromium.googlesource.com/chromium/deps/icu/+log/85814e1..585942f

Cherry-pick PR2084 fix C++20 enum issues (Frank Tang)
https://chromium.googlesource.com/chromium/deps/icu/+/585942f

R=v8-waterfall-sheriff@grotations.appspotmail.com,mtv-sf-v8-sheriff@grotations.appspotmail.com,ftang@chromium.org

Change-Id: I390adb38bca23243559916323c966b90b1995b29
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3634549
Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Bot-Commit: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#80436}

DEPS

@@ -240,7 +240,7 @@ deps = {
   'third_party/googletest/src':
     Var('chromium_url') + '/external/github.com/google/googletest.git' + '@' + 'af29db7ec28d6df1c7f0f745186884091e602e07',
   'third_party/icu':
-    Var('chromium_url') + '/chromium/deps/icu.git' + '@' + '85814e1af52482199a13d284545623ffbc9eef83',
+    Var('chromium_url') + '/chromium/deps/icu.git' + '@' + '585942f33d939a11f4600bd5042649b7ca189008',
   'third_party/instrumented_libraries':
     Var('chromium_url') + '/chromium/src/third_party/instrumented_libraries.git' + '@' + 'e09c4b66b6e87116eb190651421f1a6e2f3b9c52',
   'third_party/ittapi': {