devel/rust-analyzer: Update to 2021-08-30
Changes:
https://rust-analyzer.github.io/thisweek/2021/06/28/changelog-83.html
https://rust-analyzer.github.io/thisweek/2021/07/05/changelog-84.html
https://rust-analyzer.github.io/thisweek/2021/07/12/changelog-85.html
https://rust-analyzer.github.io/thisweek/2021/07/19/changelog-86.html
https://rust-analyzer.github.io/thisweek/2021/07/26/changelog-87.html
https://rust-analyzer.github.io/thisweek/2021/08/02/changelog-88.html
https://rust-analyzer.github.io/thisweek/2021/08/09/changelog-89.html
https://rust-analyzer.github.io/thisweek/2021/08/16/changelog-90.html
https://rust-analyzer.github.io/thisweek/2021/08/23/changelog-91.html
https://rust-analyzer.github.io/thisweek/2021/08/30/changelog-92.html