Test all SQ supported Rubies

Updates the ruby test matrix to test the
following Rubies:
* SQ minimum supported version of Ruby: 3.1.6
  - this is the terminal version of Ruby 3.1 which is due
to EOL 3/31/25
* First and last version Ruby 3.2: 3.2.0 and 3.2.4
* Every version of Ruby 3.3: 3.3.0 - 3.3.6
* Every version of Ruby 3.4: 3.4.0 - 3.4.1

Updates gemspec for zeitwerk version requirement.
Ruby 3.1.6 requires an older version of zeitwerk.

Author: hms

.github/workflows/main.yml

@@ -1,5 +1,5 @@
 name: Build
-on: [push, pull_request]
+on: [ push, pull_request ]
 
 jobs:
   rubocop:
@@ -22,8 +22,19 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: [3.3.5]
-        database: [mysql, postgres, sqlite]
+        ruby-version:
+        - 3.1.6
+        - 3.2.0
+        - 3.2.4
+        - 3.3.0
+        - 3.3.1
+        - 3.3.2
+        - 3.3.4
+        - 3.3.5
+        - 3.3.6
+        - 3.4.0
+        - 3.4.1
+        database: [ mysql, postgres, sqlite ]
     services:
       mysql:
         image: mysql:8.0.31

solid_queue.gemspec

@@ -39,4 +39,8 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rubocop-rails-omakase"
   spec.add_development_dependency "rdoc"
   spec.add_development_dependency "logger"
+
+  if Gem::Version.new(RUBY_VERSION) < Gem::Version.new("3.2")
+    spec.add_development_dependency "zeitwerk", "2.6.0"
+  end
 end