Bump dubbo from 2.5.3 to 2.6.12 in /dubbo-learn#7

dependabot[bot] wants to merge 1 commit intomasterNeumann789/springboot-learn:masterfrom

dependabot/maven/dubbo-learn/com.alibaba-dubbo-2.6.12Neumann789/springboot-learn:dependabot/maven/dubbo-learn/com.alibaba-dubbo-2.6.12Copy head branch name to clipboard