devel/mill: Update to 0.9.11

Changelog

• BSP: Fixed/improved source item for root project
• Bloop: Prevent compilation during bloop config generation
• GenIdea: Fix content path of root project (mill-build)
• Various version bumps
• Some feature backports from mill 0.10
• New + separator to provide multiple targets (with parameters) via cmdline
• New --import cmdline option to run ad-hoc plugins without editing of build.sc
• import $ivy support $MILL_BIN_PLATFORM variable and a new sort notations for external plugins
• zinc worker: Updated log4j2 to 2.16.0 to fix Log4Shell (CVE-2021-44228) vulnerability

PR: 260634
(cherry picked from commit 66134d11e66140da4c48e667168a8690a81e6ec2)