Fix linter to use the new PHP versions

Author: aristath

.github/workflows/lint.yml

@@ -26,7 +26,7 @@ jobs:
       matrix:
         # Lint against the highest/lowest supported versions of each PHP major.
         # And also do a run against "nightly" (the current dev version of PHP).
-        php_version: ['7.4', '8.0', '8.1', '8.2']
+        php_version: ['8.0', '8.1', '8.2', '8.3', '8.4']
 
     name: "Lint: PHP ${{ matrix.php_version }}"
 
@@ -37,7 +37,7 @@ jobs:
       - name: Install PHP for the composer install
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 7.4
+          php-version: ${{ matrix.php_version }}
           coverage: none
 
       # The lint stage doesn't use code style, so no need for WPCS or phpcompatibility.