Update Ruby from 2.5 to 2.7 in Dockerfile templates

Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

changelogs/unreleased/update-ruby-in-dockerfile-templates.yml

+---
+title: Update Ruby from 2.5 to 2.7 in Dockerfile templates
+merge_request: 59345
+author: Takuya Noguchi
+type: changed

vendor/Dockerfile/Ruby-alpine.Dockerfile

-FROM ruby:2.5-alpine
+FROM ruby:2.7-alpine
 
 # Edit with nodejs, mysql-client, postgresql-client, sqlite3, etc. for your needs.
 # Or delete entirely if not needed.

vendor/Dockerfile/Ruby.Dockerfile

-FROM ruby:2.5
+FROM ruby:2.7
 
 # Edit with nodejs, mysql-client, postgresql-client, sqlite3, etc. for your needs.
 # Or delete entirely if not needed.