Rollup merge of #46870 - ffflorian:fix/slice/typo, r=rkruppe
Rollup merge of #46870 - ffflorian:fix/slice/typo, r=rkruppe

docs(slice): Clarification in binary_search_by

This PR ~fixes a small comment typo~ adds some clarification to a half-open interval in the `binary_search_by` function in `slice`.

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