ci: Use ENABLE_GITHUB_ACTIONS_MARKUP instead of GITHUB_ACTIONS

To avoid CRuby's configure script to use nested groups, which is not
supported by GitHub Actions yet.

Author: kateinoigakukun

.github/workflows/build.yml

@@ -121,7 +121,7 @@ jobs:
         run: rake ${{ matrix.entry.prerelease }}[${{ inputs.prerel_name }}]
         if: ${{ inputs.prerel_name != '' && matrix.entry.prerelease != '' }}
       - name: rake ${{ matrix.entry.task }}
-        run: docker run -v "$GITHUB_WORKSPACE:/home/me/build" -w /home/me/build -e "GITHUB_ACTIONS=$GITHUB_ACTIONS" -e "RUBYWASM_UID=$(id -u)" -e "RUBYWASM_GID=$(id -g)" -e "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" ${{ steps.builder-image.outputs.imageid }} rake --verbose ${{ matrix.entry.task }}
+        run: docker run -v "$GITHUB_WORKSPACE:/home/me/build" -w /home/me/build -e "ENABLE_GITHUB_ACTIONS_MARKUP=true" -e "RUBYWASM_UID=$(id -u)" -e "RUBYWASM_GID=$(id -g)" -e "GNUMAKEFLAGS=-j$((1 + $(nproc --all)))" ${{ steps.builder-image.outputs.imageid }} rake --verbose ${{ matrix.entry.task }}
       - name: rake ${{ matrix.entry.test }}
         run: rake ${{ matrix.entry.test }}
         if: ${{ matrix.entry.test != '' }}

lib/ruby_wasm/build.rb

@@ -7,6 +7,7 @@ module RubyWasm
   class BuildExecutor
     def initialize(verbose: false)
       @verbose = verbose
+      @github_actions_markup = ENV["ENABLE_GITHUB_ACTIONS_MARKUP"] != nil
     end
 
     def system(*args, chdir: nil, out: nil, env: nil)
@@ -42,7 +43,7 @@ def system(*args, chdir: nil, out: nil, env: nil)
 
     def begin_section(klass, name, note)
       message = "\e[1;36m==>\e[0m \e[1m#{klass}(#{name}) -- #{note}\e[0m"
-      if ENV["GITHUB_ACTIONS"]
+      if @github_actions_markup
         puts "::group::#{message}"
       else
         puts message
@@ -57,7 +58,7 @@ def begin_section(klass, name, note)
 
     def end_section(klass, name)
       took = Time.now - @start_times[[klass, name]]
-      if ENV["GITHUB_ACTIONS"]
+      if @github_actions_markup
         puts "::endgroup::"
       end
       puts "\e[1;36m==>\e[0m \e[1m#{klass}(#{name}) -- done in #{took.round(2)}s\e[0m"

sig/ruby_wasm/build.rbs

@@ -223,6 +223,7 @@ module RubyWasm
 
   class BuildExecutor
     @verbose: bool
+    @github_actions_markup: bool
     @start_times: Hash[[Class, String], Time]
 
     def initialize: (?verbose: bool) -> void