adjust unit test settings for time limits

Some tests were testing a bug that caused an infinite loop.

Annotate those tests with large, small annotations.

Turn on enforceTimeLimit, failOnWarning and failOnRisky so that the
annotations are enforced when unit tests are run.

Add phpunit/php-invoker to the composer require-dev becaause this is
required to make the enforceTimeLimit setting effective.

Author: phil-davis

composer.json

@@ -39,6 +39,7 @@
     "require-dev" : {
         "friendsofphp/php-cs-fixer": "~2.17.1",
         "phpunit/phpunit" : "^7.5 || ^8.5 || ^9.0",
+        "phpunit/php-invoker" : "^2.0 || ^3.1",
         "phpstan/phpstan": "^0.12"
     },
     "suggest" : {

tests/VObject/Component/VCalendarTest.php

@@ -350,6 +350,13 @@ public function testBrokenEventExpand()
         );
     }
 
+    /**
+     * This test used to induce an infinite loop.
+     * The "medium" annotation means that phpunit will fail the
+     * test if it takes longer than a default of 10 seconds.
+     *
+     * @medium
+     */
     public function testEventExpandYearly()
     {
         $input = 'BEGIN:VCALENDAR

tests/VObject/Recur/RRuleIteratorTest.php

@@ -892,6 +892,13 @@ public function testMinusFifthThursday()
         );
     }
 
+    /**
+     * This test can take some seconds to complete.
+     * The "large" annotation means phpunit will let it run for
+     * up to 60 seconds by default.
+     *
+     * @large
+     */
     public function testNeverEnding()
     {
         $this->parse(

tests/phpunit.xml

@@ -6,6 +6,9 @@
   convertWarningsToExceptions="true"
   beStrictAboutTestsThatDoNotTestAnything="true"
   beStrictAboutOutputDuringTests="true"
+  failOnRisky="true"
+  failOnWarning="true"
+  enforceTimeLimit="true"
   >
   <testsuites>
     <testsuite name="Sabre\VObject">