gencache fails to build with ICU76

[carstene1ns]

ICU has cleaned up their pkg-config files, icu-uc will not get added automatically anymore.

Should be enough to add this in configure.ac, though is untested here:

PKG_CHECK_MODULES([ICU], [icu-i18n icu-uc])

[Ghabry]

can confirm that this works.

~/P/e/e/gencache> autoreconf -fi
~/P/e/e/gencache> ./configure
checking for a BSD-compatible install... /usr/bin/install -c
checking whether sleep supports fractional seconds... yes
checking filesystem timestamp resolution... 0.01
checking whether build environment is sane... yes
checking for a race-free mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking xargs -n works... yes
checking whether make supports the include directive... yes (GNU style)
checking for g++... g++
checking whether the C++ compiler works... yes
checking for C++ compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether the compiler supports GNU C++... yes
checking whether g++ accepts -g... yes
checking for g++ option to enable C++11 features... none needed
checking dependency style of g++... gcc3
checking how to run the C++ preprocessor... g++ -E
checking whether the compiler supports GNU C++... (cached) yes
checking whether g++ accepts -g... (cached) yes
checking for g++ option to enable C++11 features... (cached) none needed
checking dependency style of g++... (cached) gcc3
checking for pkg-config... /usr/bin/pkg-config
checking pkg-config is at least version 0.9.0... yes
checking for icu-i18n icu-uc... yes
checking for nlohmann_json... yes
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: executing depfiles commands
~/P/e/e/gencache> make -j12
  CXX      src/gencache-main.o
  CXXLD    gencache
~/P/e/e/gencache>