Update actions/checkout to v3

Author: Eremeev Ales

.github/workflows/tests.yml

@@ -10,7 +10,7 @@ jobs:
  name: Tests on PHP 7.4
  steps:
  - name: Checkout code
- uses: actions/checkout@v2
+ uses: actions/checkout@v3
 
  - name: Setup PHP
  uses: shivammathur/setup-php@v2
@@ -30,7 +30,7 @@ jobs:
  name: Tests on PHP 8.0
  steps:
  - name: Checkout code
- uses: actions/checkout@v2
+ uses: actions/checkout@v3
 
  - name: Setup PHP
  uses: shivammathur/setup-php@v2
@@ -51,7 +51,7 @@ jobs:
  name: Tests on PHP 8.1
  steps:
  - name: Checkout code
- uses: actions/checkout@v2
+ uses: actions/checkout@v3
 
  - name: Setup PHP
  uses: shivammathur/setup-php@v2