Update gem date

Author: KitaitiMakoto

bindings/ruby/whispercpp.gemspec

@@ -4,7 +4,7 @@ Gem::Specification.new do |s|
   s.name    = "whispercpp"
   s.authors = ["Georgi Gerganov", "Todd A. Fisher"]
   s.version = '1.3.2'
-  s.date    = '2025-04-25'
+  s.date    = '2025-05-01'
   s.description = %q{High-performance inference of OpenAI's Whisper automatic speech recognition (ASR) model via Ruby}
   s.email   = '[email protected]'
   s.extra_rdoc_files = ['LICENSE', 'README.md']