Prepare common data model 0.4

[lupemba]

This PR requires: https://github.com/JuliaGeo/CommonDataModel.jl/pull/35

The PR is related to the following issues https://github.com/JuliaGeo/CommonDataModel.jl/issues/32 and https://github.com/JuliaGeo/NCDatasets.jl/issues/274

Content

• Bump CommonDataModel to 0.4 (Not merged yet).
• Remove DiskArrays.@implement_diskarray. Variable is now a subtype of AbstractDiskArray so this is not needed anymore.
• Remove the custom code for subsub used for views. This is not needed anymore since the DiskArrays views are now used.

[lupemba]

The PR have been tested offline by

• Clone https://github.com/JuliaGeo/CommonDataModel.jl/pull/35
• Use Pkg dev to add the local repo as dependency
• Run tests.

All tests pass on my MacOS, Julia 1.11

[Alexander-Barth]

Thanks a lot Simon for your great work! I am merging your PR.

[felixcremer]

Can we register this change? Is this breaking or not?