[DOC] Exclude non-updated stdlibs since the previous release

.github/workflows/check_misc.yml

@@ -22,19 +22,48 @@ jobs:
             git grep -l -F -e $header -e HAVE_`echo $header | tr a-z./ A-Z__` -- . > /dev/null || echo $header
           done | grep -F .
         working-directory: include
-      - name: Maintain updated default gem list
+
+      - name: Download default gems list
         run: |
-          news = File.read("NEWS.md")
+          curl -O https://stdgems.org/default_gems.json
+
+      - name: Make default gems list
+        run: |
+          require 'rubygems'
           $:.unshift "lib"
-          gems = Dir.glob("{ext,lib}/**/*.gemspec").map {|f|
+          rgver = File.foreach("lib/rubygems.rb") do |line|
+            break $1 if /^\s*VERSION\s*=\s*"([^"]+)"/ =~ line
+          end
+          gems = Dir.glob("{ext,lib}/**/*.gemspec").map do |f|
             spec = Gem::Specification.load(f)
-            [spec.name, spec.version]
-          }.sort
-          news.sub!(/^\*\s+The following default gem are updated\.\K(\n\s+\*\s+)((?i:RubyGems))(?:\1.*)*/) do
-            ["", $2, gems.map {|*spec| spec.join(" ")}].join($1)
+            "#{spec.name} #{spec.version}"
+          end.sort
+          File.open("stdlibs", "w") do |f|
+            f.puts "RubyGems #{rgver}"
+            f.puts gems
+          end
+        shell: ruby --disable=gems {0}
+
+      - name: Maintain updated default gems list in NEWS
+        run: |
+          require 'json'
+          news = File.read("NEWS.md")
+          prev = news[/since the \*+(\d+\.\d+\.\d+)\*+/, 1]
+          prevs = [prev, prev.sub(/\.\d+\z/, '')]
+          last = JSON.parse(File.read("default_gems.json"))['gems'].filter_map do |g|
+            v = g['versions'].values_at(*prevs).compact.first
+            g = g['gem']
+            g == 'RubyGems' if g == 'rubygems'
+            "#{g} #{v}" if v
+          end
+          new = File.readlines('stdlibs', chomp: true).grep_v(/^#/)
+          gems = new - last
+          news.sub!(/^\*\s+The following default gems? are updated\.\K(\n\s+\*\s+).*(?:\1.*)*/) do
+            ["", gems].join($1)
           end or exit
           File.write("NEWS.md", news)
         shell: ruby {0}
+
       - name: Check diffs
         id: diff
         run: |