[BUGFIX] Add recipient to FluidEmail Test cases to avoid errors

The to header is mandatory by now, so we need to supply the recipient
in our testcases now.

Resolves: #91346
Releases: master
Change-Id: Ic1a3197a8412b27eb5cebb00a1443f10021b9326
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64438
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>

typo3/sysext/core/Tests/Functional/Mail/FluidEmailTest.php

@@ -32,7 +32,8 @@ public function settingFormatWithTextOnlyGeneratesTextEmail()
             ->format(FluidEmail::FORMAT_PLAIN)
             ->setTemplate('Default')
             ->from('benniYYYY@typo3.org')
-            ->assign('content', 'Plain content from Functional test');
+            ->assign('content', 'Plain content from Functional test')
+            ->to('some-recipient@example.com');
         $result = $subject->getBody();
         self::assertEquals('plain', $result->getMediaSubtype());
         self::assertStringContainsString('Plain content from Functional test', $result->bodyToString());
@@ -50,7 +51,8 @@ public function settingFormatWithHtmlOnlyGeneratesHtmlEmail()
             ->format(FluidEmail::FORMAT_HTML)
             ->setTemplate('Default')
             ->from('benniYYYY@typo3.org')
-            ->assign('content', 'HTML content <strong>from</strong> Functional test');
+            ->assign('content', 'HTML content <strong>from</strong> Functional test')
+            ->to('some-recipient@example.com');
         $result = $subject->getBody();
         self::assertEquals('html', $result->getMediaSubtype());
         self::assertStringContainsString('&lt;strong&gt;from&lt;/strong&gt;', $result->bodyToString());
@@ -68,7 +70,8 @@ public function settingFormatWithTextAndHtmlGeneratesTwoBodies()
             ->format(FluidEmail::FORMAT_BOTH)
             ->setTemplate('Default')
             ->from('benniYYYY@typo3.org')
-            ->assign('content', 'Plain content <strong>from</strong> Functional test');
+            ->assign('content', 'Plain content <strong>from</strong> Functional test')
+            ->to('some-recipient@example.com');
         $result = $subject->getBody();
         self::assertEquals('alternative', $result->getMediaSubtype());
         self::assertStringContainsString('&lt;strong&gt;from&lt;/strong&gt;', $result->bodyToString());