Inflection-120 Update ICU version in versions.mk to 77.1

[FrankYFTang]

Address #120

[FrankYFTang]

so simply specified the version number is not enough, we need to change the folloiwng line
sudo apt-get update && sudo apt-get install -y libicu-dev icu-devtools

in .github/workflows/cmake-multi-platform.yml to install 77.1

One possible way is to wget the tar ball and unzip from github as
download_77_1
in https://github.com/unicode-org/conformance/blob/main/setup.sh
then do https://github.com/unicode-org/conformance/blob/main/executors/cpp/set_icu4c_binary.sh

to set up

[grhoten]

I approve in principle. Please get the pipeline passing before merging. I suspect that the ICU_ROOT is missing the "local" part of the path. The PATH and LD_LIBRARY_PATH should not be necessary to change.

[nciric]

We probably don't need this line.