Disable 2 Tests

Test for url image used file_get_contents on file which we have read successfully for years. Today it started returning error 403. Disable tests while I study whether there is a suitable replacement.

Author: oleibman

tests/PhpSpreadsheetTests/Reader/Xlsx/URLImageTest.php

@@ -12,7 +12,8 @@
 
 class URLImageTest extends TestCase
 {
-    public function testURLImageSource(): void
+    // https://github.com/readthedocs/readthedocs.org/issues/11615
+    public function xtestURLImageSource(): void
     {
         if (getenv('SKIP_URL_IMAGE_TEST') === '1') {
             self::markTestSkipped('Skipped due to setting of environment variable');
@@ -43,7 +44,7 @@ public function testURLImageSource(): void
         }
     }
 
-    public function testURLImageSourceNotFound(): void
+    public function xtestURLImageSourceNotFound(): void
     {
         if (getenv('SKIP_URL_IMAGE_TEST') === '1') {
             self::markTestSkipped('Skipped due to setting of environment variable');