vincepri: 🌱 Upgrade mdbook to v0.4.11

JobBuild
5023
07-27 20:55
pull-cluster-api-apidiff-main 1420125605004840960
pull-cluster-api-build-main 1420125604971286528
pull-cluster-api-test-main 1420128124456144896 1420125605071949824
pull-cluster-api-verify 1420125605042589696