[R] Implement bindings for lubridate::leap_year

[asfimport]

This can be done by combining expressions

Reporter: Nicola Crane / @thisisnic
Assignee: Danielle Navarro / @djnavarro
Watchers: Rok Mihevc / @rok

PRs and other links:

• GitHub Pull Request #12173
• GitHub Pull Request #12598

_{Note: This issue was originally created as ARROW-14823. Please see the migration documentation for further details.}

[asfimport]

Nicola Crane / @thisisnic:
Issue resolved by pull request 12173
#12173

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Rok Mihevc / @rok:
Would it make sense to remap this to c++ binding now that it's available? #12373

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Danielle Navarro / @djnavarro:
yes, absolutely! I assume the correct procedure is to open a new PR and linking back to this issue?

[asfimport]

Rok Mihevc / @rok:
Yeah, that's neatest. You could also open another PR under this ID stating it's a follow up if you're lazy.