[Docs/CMake] Set CMake minimum to 3.30 everywhere

[philippremy]

Just a small fix (especially for docs) to accomodate for the change introduced in a2fea48, which set the minimum CMake version to 3.30.

Something we could consider is to hard-error on any CMake 4.X, because at least when building some embedded dependencies it can cause problems. However, I don't know if AliceVision itself can handle CMake 4.X and I cannot really test that, because I only have a Mac and must always build all dependencies. I therefore left it as-is and only kept the upper bound for building on Apple platforms.

[servantftransperfect]

I do use cmake 4+ daily and av is working correctly. The process of upgrading the dependencies is ongoing.

[philippremy]

I do use cmake 4+ daily and av is working correctly. The process of upgrading the dependencies is ongoing.

That is good to hear! Some dependencies will probably never be compatible (flann for example), because they seem to be not maintained. But I already experimented with overlaying CMakeLists.txt... something I am considering for the build system rewrite.

[servantftransperfect]

For those dependencies, we "maintain" forks on aliceVision.

[philippremy]

Right, I thought that only applied to non-CMake based dependencies. Makes my life even easier :D.

[servantftransperfect]

Thanks, merged