Add back 2.5 so clean gem install rails works again

Author: kaspth

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ 2.6, 2.7 ]
+        ruby: [ 2.5, 2.6, 2.7 ]
         rails: [ '5.0', '5.1', '5.2', '6.0', '6.1' ]
         include:
           - ruby: '3.0'

globalid.gemspec

@@ -5,7 +5,7 @@ Gem::Specification.new do |s|
   s.summary     = 'Refer to any model with a URI: gid://app/class/id'
   s.description = 'URIs for your models makes it easy to pass references around.'
 
-  s.required_ruby_version = '>= 2.6.0'
+  s.required_ruby_version = '>= 2.5.0'
 
   s.license = 'MIT'