:octocat: run phan on matrix.php-version

.github/workflows/tests.yml

@@ -47,7 +47,7 @@ jobs:
         uses: ramsey/composer-install@v2
 
       - name: "Run phan"
-        run: php vendor/bin/phan
+        run: php vendor/bin/phan --target-php-version=${{ matrix.php-version }}
 
 
   build-docs:

.phan/config.php

@@ -14,7 +14,8 @@ return [
 	// Note that the **only** effect of choosing `'5.6'` is to infer
 	// that functions removed in php 7.0 exist.
 	// (See `backward_compatibility_checks` for additional options)
-	'target_php_version' => '7.4',
+	'target_php_version' => null,
+	'minimum_target_php_version' => '7.4',
 
 	// A list of directories that should be parsed for class and
 	// method information. After excluding the directories