Add push workflow and update release rake task

Author: sferik

.github/workflows/push.yml

@@ -0,0 +1,27 @@
+name: Push gem to RubyGems
+
+on:
+  push:
+    tags:
+      - "v*"
+
+permissions:
+  contents: read
+
+jobs:
+  push:
+    if: github.repository == 'sferik/x-ruby'
+    runs-on: ubuntu-latest
+    environment:
+      name: rubygems.org
+      url: https://rubygems.org/gems/x
+    permissions:
+      contents: write
+      id-token: write
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ruby
+          bundler-cache: true
+      - uses: rubygems/release-gem@v1

Rakefile

@@ -1,4 +1,9 @@
 require "bundler/gem_tasks"
+
+# Override release task to skip gem push (handled by GitHub Actions)
+Rake::Task["release"].clear
+desc "Create tag and push to GitHub (gem push handled by CI)"
+task release: %w[release:guard_clean release:source_control_push]
 require "rake/testtask"
 
 Rake::TestTask.new(:test) do |t|