Bump @springio/antora-zip-contents-collector-extension from 1.0.0-alpha.8 to 1.0.0-alpha.9 in /antora#15

dependabot[bot] wants to merge 1 commit intomainscottfrederick/spring-boot:mainfrom

dependabot/npm_and_yarn/antora/springio/antora-zip-contents-collector-extension-1.0.0-alpha.9scottfrederick/spring-boot:dependabot/npm_and_yarn/antora/springio/antora-zip-contents-collector-extension-1.0.0-alpha.9Copy head branch name to clipboard