fix: update CI runner from deprecated ubuntu-20.04 to ubuntu-latest

.github/workflows/tests.yml

@@ -9,11 +9,11 @@ on:
 jobs:
   tests:
     name: Tests
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: true
       matrix:
-        php: ['8.3', '8.4', '8.5']
+        php: ["8.3", "8.4", "8.5"]
         stability: [prefer-stable]
 
     steps:
@@ -35,6 +35,5 @@ jobs:
           max_attempts: 5
           command: composer update --${{ matrix.stability }} --prefer-dist --no-interaction --no-progress ${{ matrix.flags }}
 
-
       - name: Execute tests
-        run: vendor/bin/pest
+        run: vendor/bin/pest