Drop required_ruby_version from gemspec

Ruby version support is now driven by the per-Rails gemfile matrix in
test_gemfiles.yml, which exercises Ruby versions as low as 2.4. The
hard-coded >= 3.2 floor in the gemspec blocked bundle install on any
of those older Ruby rows.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yahonda

ruby-plsql.gemspec

@@ -10,7 +10,6 @@ Gem::Specification.new do |s|
   s.version = "0.8.0"
 
   s.required_rubygems_version = Gem::Requirement.new(">= 0".freeze) if s.respond_to? :required_rubygems_version=
-  s.required_ruby_version = ">= 3.2"
   s.require_paths = ["lib".freeze]
   s.authors = ["Raimonds Simanovskis".freeze]
   s.date = "2018-09-03"