Bump futures-util from 0.3.1 to 0.3.21#12

dependabot[bot] wants to merge 1 commit intomasterdarkwisebear/dorkfs:masterfrom

dependabot/cargo/futures-util-0.3.21darkwisebear/dorkfs:dependabot/cargo/futures-util-0.3.21Copy head branch name to clipboard