Update Ubuntsu version

Author: ma2yama

.github/workflows/CI.yml

@@ -8,7 +8,7 @@ jobs:
 
   check-and-test:
 
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

.github/workflows/build.yml

@@ -8,7 +8,7 @@ on: push
 
 jobs:
   check-and-test:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4