Drop support for Ruby <3.2

We're looking into compatibility issues with a recent release of the
govuk_publishing_components gem. Unfortunately, since the components gem
dropped support for Ruby <3.2 in its own 41.1.0 release (August 2024),
we need to use a newer version of Ruby to be able to actually reproduce
the problem.

While updating the .ruby-version (to 3.2.2, same as
govuk_publishing_components), it seems sensible to update the minimum
supported Ruby version to match it.

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [3.1, 3.2, 3.3]
+        ruby: [3.2, 3.3]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4

.ruby-version

@@ -1 +1 @@
-3.1.4
+3.2.2

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+* Drop support for Ruby <3.2
+
 ## 9.0.0
 
 * Remove Advisory component ([#357](https://github.com/alphagov/govspeak/pull/357))

govspeak.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |s|
   s.summary       = "Markup language for single domain"
   s.description   = 'A set of extensions to markdown layered on top of the kramdown
 library for use in the UK Government Single Domain project'
-  s.required_ruby_version = ">= 3.1.4"
+  s.required_ruby_version = ">= 3.2"
 
   s.files = Dir[
     "lib/**/*",