Merge pull request #1797 from freeCodeCamp/renovate/ruby-2.x

chore(deps): update ruby docker tag to v2.7.6

Dockerfile-alpine

@@ -1,4 +1,4 @@
-FROM ruby:2.6.5-alpine
+FROM ruby:2.7.6-alpine
 
 ENV LANG=C.UTF-8
 ENV ENABLE_SERVICE_WORKER=true