rm Ruby 2.4 support to address rexml CVE, add Ruby 3.3 support

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
       matrix:
         # Due to https://github.com/actions/runner/issues/849, we have to use
         # quotes for '3.0' -- without quotes, CI sees '3' and runs the latest.
-        ruby: [2.4, 2.5, 2.6, 2.7, '3.0', 3.1, 3.2, jruby, truffleruby-head]
+        ruby: [2.5, 2.6, 2.7, '3.0', 3.1, 3.2, 3.3, jruby, truffleruby-head]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4

.ruby-version

@@ -1 +1 @@
-3.2.2
+3.3.1

Gemfile.lock

@@ -33,7 +33,7 @@ GEM
     rake (13.1.0)
     redcarpet (3.6.0)
     regexp_parser (2.8.0)
-    rexml (3.2.5)
+    rexml (3.2.6)
     rouge (4.1.0)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
@@ -54,7 +54,7 @@ GEM
       parser (>= 3.2.0.0)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
-      rexml (>= 3.2.5, < 4.0)
+      rexml (>= 3.2.6, < 4.0)
       rubocop-ast (>= 1.28.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)

memo_wise.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |spec|
     "[email protected]",
   ]
 
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.4.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.5.0")
 
   # Specify which files should be added to the gem when it is released.
   # The `git ls-files -z` loads the files in the RubyGem that have been added