Pass the $diff to show_result for GHA support

Author: TimWolla

run-tests.php

@@ -2749,7 +2749,7 @@ function run_test(string $php, $file, array $env): string
         show_file_block('mem', file_get_contents($memcheck_filename));
     }
 
-    show_result(implode('&', $restype), $tested, $tested_file, $info);
+    show_result(implode('&', $restype), $tested, $tested_file, $info, $diff);
 
     foreach ($restype as $type) {
         $PHP_FAILED_TESTS[$type . 'ED'][] = [
@@ -3276,7 +3276,8 @@ function show_result(
     string $result,
     string $tested,
     string $tested_file,
-    string $extra = ''
+    string $extra = '',
+    string $diff = ''
 ): void {
     global $SHOW_ONLY_GROUPS, $colorize, $github_actions;
 
@@ -3303,6 +3304,7 @@ function show_result(
 
         if ($github_actions) {
             $title = $tested;
+            $message = '';
 
             $type = null;
             switch ( $result ) {
@@ -3328,6 +3330,8 @@ function show_result(
                     break;
             }
 
+            $message .= "\n\n{$diff}";
+
             if ($type !== null) {
                 $title = strtr($title, [
                     "%" => '%25',