Fix build with ICU 76

Due to unicode-org/icu@199bc82, ICU 76 no longer adds `icu-uc` by
default. This causes linker errors for undefined symbols like
`icu_76::UnicodeString::doReplace(...)`, referenced from:
`zim::removeAccents(...)` in tools.cpp.o.

Meson will automatically flatten the dependencies list as documented
at https://mesonbuild.com/Reference-manual_functions.html#build_target

meson.build

@@ -77,9 +77,15 @@ else
 endif
 
 if xapian_dep.found()
-    icu_dep = dependency('icu-i18n', static:static_linkage)
+    icu_dep = [
+        dependency('icu-i18n', static:static_linkage),
+        dependency('icu-uc', static:static_linkage)
+    ]
 else
-    icu_dep = dependency('icu-i18n', required:false, static:static_linkage)
+    icu_dep = [
+        dependency('icu-i18n', required:false, static:static_linkage),
+        dependency('icu-uc', required:false, static:static_linkage)
+    ]
 endif
 
 gtest_dep = dependency('gtest', version: '>=1.10.0', main:true, fallback:['gtest', 'gtest_main_dep'], required:false)