Rollup merge of #80448 - m-ou-se:deque-range-version, r=m-ou-se
Rollup merge of #80448 - m-ou-se:deque-range-version, r=m-ou-se

Fix stabilization version of deque_range feature.

See https://github.com/rust-lang/rust/pull/79022#issuecomment-751315315

graydon/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust