Stick with icu4c 74.2 on macOS CI for PHP-8.1

PHP-8.1 is not ready for ICU >= 75.1 which requires C++17 support.
Thus we force the usage of icu4c@74, what is scheduled for removal in
May 2025, though.

Closes GH-16789.

.github/actions/brew/action.yml

@@ -21,7 +21,6 @@ runs:
           webp \
           freetype \
           intltool \
-          icu4c \
           libiconv \
           zlib \
           t1lib \
@@ -33,4 +32,5 @@ runs:
           libjpeg \
           libxslt \
           postgresql
+        brew reinstall icu4c@74
         brew link icu4c gettext --force

.github/actions/configure-macos/action.yml

@@ -18,7 +18,7 @@ runs:
         export PKG_CONFIG_PATH="$PKG_CONFIG_PATH:/usr/local/opt/libxml2/lib/pkgconfig"
         export PKG_CONFIG_PATH="$PKG_CONFIG_PATH:/usr/local/opt/libxslt/lib/pkgconfig"
         export PKG_CONFIG_PATH="$PKG_CONFIG_PATH:/usr/local/opt/zlib/lib/pkgconfig"
-        export PKG_CONFIG_PATH="$PKG_CONFIG_PATH:/usr/local/opt/icu4c/lib/pkgconfig"
+        export PKG_CONFIG_PATH="$PKG_CONFIG_PATH:/usr/local/opt/icu4c@74/lib/pkgconfig"
         sed -i -e 's/Requires.private:.*//g' "$BREW_OPT/curl/lib/pkgconfig/libcurl.pc"
         ./buildconf --force
         ./configure \