tools: fix update-icu.sh

The name of the sources MD5 file has changed.

Refs: https://github.com/unicode-org/icu/releases/tag/release-74-2
PR-URL: #51723
Refs: #51721
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz.nizipli@sentry.io>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Steven R Loomis <srl295@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>

tools/dep_updaters/update-icu.sh

@@ -40,7 +40,7 @@ NEW_VERSION_TGZ="icu4c-${LOW_DASHED_NEW_VERSION}-src.tgz"
 
 NEW_VERSION_TGZ_URL="https://github.com/unicode-org/icu/releases/download/release-${DASHED_NEW_VERSION}/$NEW_VERSION_TGZ"
 
-NEW_VERSION_MD5="https://github.com/unicode-org/icu/releases/download/release-${DASHED_NEW_VERSION}/icu4c-${LOW_DASHED_NEW_VERSION}-src.md5"
+NEW_VERSION_MD5="https://github.com/unicode-org/icu/releases/download/release-${DASHED_NEW_VERSION}/icu4c-${LOW_DASHED_NEW_VERSION}-sources.md5"
 
 CHECKSUM=$(curl -sL "$NEW_VERSION_MD5" | grep "$NEW_VERSION_TGZ" | grep -v "\.asc$" | awk '{print $1}')