Write the matrix to a file instead of stdout

Author: kateinoigakukun

.github/workflows/build.yml

@@ -90,8 +90,8 @@ jobs:
       - name: Set matrix
         id: set-matrix
         run: |
-          rake ci:rake_task_matrix > matrix.json
-          echo "entries=$(cat matrix.json)" >> $GITHUB_OUTPUT
+          rake ci:rake_task_matrix
+          echo "entries=$(cat ci_matrix.json)" >> $GITHUB_OUTPUT
 
   rake-tasks:
     strategy:

rakelib/ci.rake

@@ -95,7 +95,8 @@ end
 
 namespace :ci do
   task :rake_task_matrix do
-    print JSON.generate(rake_task_matrix.flat_map { |_, entries| entries })
+    content = JSON.generate(rake_task_matrix.flat_map { |_, entries| entries })
+    File.write("ci_matrix.json", content)
   end
 
   task :pin_build_manifest do