Devcontainer build error because of cmake update

[nnWhisperer]

When I try to create a devcontainer from this repo, I receive the following:

RUN CC=clang-13 CXX=clang++-13 cmake -S /home/iwyu/include-what-you-use         -B /home/iwyu/build         -G "Unix Makefiles" -DCMAKE_PREFIX_PATH=/usr/lib/llvm-13 &&     cmake --build /home/iwyu/build -j &&     cmake --install /home/iwyu/build:
0.274   Compatibility with CMake < 3.5 has been removed from CMake.
0.274 
0.274   Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
0.274   to tell CMake that the project requires at least <min> but has been updated
0.274   to work with policies introduced by <max> or earlier.
0.274 
0.274   Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.
0.274 
0.274 
0.275 -- Configuring incomplete, errors occurred!

When I check the related repo, it seems that its cmake minimum is already 3.20 since very long time ~ 2 years.
Considering that there might be a cmake bug that thinks 3.20 < 3.5, because of cmake's possible version parsing errors, I even attempted continuing the build with sed replacing the minimum version 3.20 with 3.9 but the same problem still persists. How to proceed? It should have already been working though :(

[nnWhisperer]

I traced it further, it's related to the LLVM version. I guess it is time to update the devcontainer from focal to noble and LLVM to 20 and GCC to 13.