Rollup merge of #98411 - ehuss:update-tendril, r=Mark-Simulacrum

Rollup merge of #98411 - ehuss:update-tendril, r=Mark-Simulacrum

Update tendril

The 0.4.1 version of `tendril` (used by mdbook) triggers the `unaligned_references` lint which is now reported as a future-compatibility warning as of #95372. This updates it to 0.4.3 which does not trigger the warning. This update also triggered the update of `futf` from 0.1.4 to 0.1.5.

tendril changes: https://github.com/servo/tendril/compare/v0.4.1...v0.4.3
futf changes: https://github.com/servo/futf/compare/v0.1.4...v0.1.5