LibUnicode: Update ICU to 78.2

Contains fixes needed for non-ISO-8601 calendars in Temporal.

Libraries/LibUnicode/CMakeLists.txt

@@ -24,7 +24,7 @@ set(GENERATED_SOURCES ${CURRENT_LIB_GENERATED})
 
 ladybird_lib(LibUnicode unicode)
 
-find_package(ICU 78 REQUIRED COMPONENTS data i18n uc)
+find_package(ICU 78.2 EXACT REQUIRED COMPONENTS data i18n uc)
 target_link_libraries(LibUnicode PRIVATE ICU::i18n ICU::uc ICU::data)
 
 # FIXME: Add support for building LibGfx in sanitize

Meta/CMake/flatpak/org.ladybird.Ladybird.json

@@ -215,7 +215,7 @@
         {
           "type": "git",
           "url": "https://github.com/unicode-org/icu.git",
-          "tag": "release-78.1"
+          "tag": "release-78.2"
         }
       ],
       "subdir": "icu4c/source/",

vcpkg.json

@@ -271,7 +271,7 @@
     },
     {
       "name": "icu",
-      "version": "78.1#1"
+      "version": "78.2#0"
     },
     {
       "name": "libavif",