[Deprecation] Replace `Element` property `is_rare_earth_metal` with `is_rare_earth` to include Y and Sc  (#3817)

* make Sc and Y rare earth ele

* update docstring

* log breaking change

* revert removal of blank line

* update grace period

* add is_rare_earth and deprecate the old

* update `monty` to use `deadline`

* update monty to latest

---------

Signed-off-by: Shyue Ping Ong <shyuep@users.noreply.github.com>
Co-authored-by: Shyue Ping Ong <shyuep@users.noreply.github.com>