[build] Update scala-library, scala-reflect to 2.12.21#107

scala-steward wants to merge 1 commit intorayrobdod:mainrayrobdod/string-context-parser-combinator:mainfrom

scala-steward:update/scala-library-2.12.21scala-steward/string-context-parser-combinator:update/scala-library-2.12.21Copy head branch name to clipboard