Attempt to fix failing unit tests that use runInSeparateProcess

Author: marcovtwout

composer.json

@@ -108,7 +108,8 @@
 			"phpunit/phpunit": {
 				"Fix PHP 7 compatibility": "https://yiisoft.github.io/phpunit-patches/phpunit_php7.patch",
 				"Fix PHP 8 compatibility": "https://yiisoft.github.io/phpunit-patches/phpunit_php8.patch",
-				"Fix PHP 8.1 compatibility": "https://yiisoft.github.io/phpunit-patches/phpunit_php81.patch"
+				"Fix PHP 8.1 compatibility": "https://yiisoft.github.io/phpunit-patches/phpunit_php81.patch",
+				"Fix PHP 8.3 compatibility": "tests/phpunit_php83.patch"
 			}
 		}
 	},

tests/phpunit_php83.patch

@@ -0,0 +1,11 @@
+--- a/src/Util/PHP/Template/TestCaseMethod.tpl.dist
++++ b/src/Util/PHP/Template/TestCaseMethod.tpl.dist
+@@ -56,7 +56,7 @@
+     }
+ 
+     @rewind(STDOUT); /* @ as not every STDOUT target stream is rewindable */
+-    if ($stdout = stream_get_contents(STDOUT)) {
++    if ($stdout = @stream_get_contents(STDOUT)) {
+         $output = $stdout . $output;
+     }
+