[ci] Fix R 3.6 tests, dask tests, compatibility with dask>=2024.3.1#6357

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jameslamb merged 8 commits intomasterfrom

Mar 18, 2024

Commits on Mar 11, 2024

[ci] Fix tests for R 3.6
borchero
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Commits on Mar 16, 2024

remove clang-18 job
jameslamb
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