Update ci.yml

Signed-off-by: NAKANISHI Kiyomaro <kiyomaro092@gmail.com>

Author: Nakakiyo092

.github/workflows/ci.yml

@@ -17,20 +17,15 @@ permissions:
 
 jobs:
   Linux:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        include:
-          - { os: ubuntu-latest,  python-version: "3.x" }
-
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.x"
 
       - name: Install dependencies
         run: |
@@ -42,20 +37,15 @@ jobs:
           python3 ./reader/reader.py --help
 
   macOS:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        include:
-          - { os: macos-latest,  python-version: "3.x" }
-
+    runs-on: macos-latest
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.x"
 
       - name: Install dependencies
         run: |
@@ -67,20 +57,15 @@ jobs:
           python3 ./reader/reader.py --help
 
   Windows:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        include:
-          - { os: windows-latest,  python-version: "3.x" }
-
+    runs-on: windows-latest
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
 
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: "3.x"
 
       - name: Install dependencies
         run: |