remove deprecated inputsplitter since 7.0 (#14573)

Backport PR #14601: Deprecate inputtransformer since 7.0

Deprecate inputtransformer since 7.0 (#14601) Actually emit deprecation warnings when using inputtransformer which is deprecated.

remove ref to inpusplit

Remove IPython.utils.tz Deprecated since IPython 8.19 (Nov 2023)

Remove deprecated inputsplitter since 7.0 All this should have been deprecated and removed for long.

docs

Deprecate inputtransformer since 7.0 Actually emit deprecation warnings when using inputtransformer which is deprecated.

Drop Python 3.10 (#14589)

Remove all references to notebooks (#14572) IPython repo is just the CLI, and those are unmaintained. Reduce the size of the repo, and if anything those should migrate to notebook or lab, or be a separate example repo.