Merge branch '6.4' into 7.1

* 6.4:
  Port Appveyor to GitHub Actions
  normalize paths to avoid failures if a path is referenced by different names
  skip autocomplete test when stty is not available
  Bump Symfony version to 6.4.15
  Update VERSION for 6.4.14
  Update CHANGELOG for 6.4.14
  Bump Symfony version to 5.4.47
  Update VERSION for 5.4.46
  Update CONTRIBUTORS for 5.4.46
  Update CHANGELOG for 5.4.46

Tests/Helper/QuestionHelperTest.php

@@ -908,6 +908,10 @@ public function testTraversableMultiselectAutocomplete()
 
     public function testAutocompleteMoveCursorBackwards()
     {
+        if (!Terminal::hasSttyAvailable()) {
+            $this->markTestSkipped('`stty` is required to test autocomplete functionality');
+        }
+
         // F<TAB><BACKSPACE><BACKSPACE><BACKSPACE>
         $inputStream = $this->getInputStream("F\t\177\177\177");