[devdocsgjs] Dockerfile: bump the ruby-alpine image used for deployment

[Andy Holmes <andyholmes src gnome org>]

commit 83a84bd4fda378530c56c9531d5e5ed53bc7f3cc
Author: Andy Holmes <andrew g r holmes gmail com>
Date:   Sun Sep 5 21:29:22 2021 -0700

    Dockerfile: bump the ruby-alpine image used for deployment
    
    The ruby:2.7.3-alpine image we use during deployment is no longer
    available. To fix this we need to bump the deployment image and allow
    for `~> 2.7.3` so the build and deployment stages can both run.

 Dockerfile | 6 +++---
 Gemfile    | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/Dockerfile b/Dockerfile
index 71ef52b1..7c205557 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -111,15 +111,15 @@ RUN for docset in appindicator301 appstreamglib10 atk10 atspi20 cairo10 \
       do echo $docset; bundle exec thor docs:generate $docset --force; done
 
 
-# We deploy in ruby:2.7.3-alpine for size
+# We deploy in ruby:2.7.4-alpine for size
 #
 # Changes from Dockerfile-alpine:
-# - Ruby 2.6.0 -> 2.7.3
+# - Ruby 2.6.0 -> 2.7.4
 # - Copy from the build-stage image instead of the current dir
 # - Update bundler CLI usage
 # - The css and javascript docsets don't resolve and have been removed
 # - User permission fixes
-FROM docker.io/library/ruby:2.7.3-alpine
+FROM docker.io/library/ruby:2.7.4-alpine
 
 ENV LANG=C.UTF-8
 
diff --git a/Gemfile b/Gemfile
index cfa12ef2..63fbdb10 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,5 @@
 source 'https://rubygems.org'
-ruby '2.7.3'
+ruby '~> 2.7.3'
 
 gem 'rake'
 gem 'thor'