handle invalid timezones Australia/ACT and Europe/Kiev - fixes azuyalabs#342

Author: kevinpapst

src/Yasumi/Provider/Australia/AustralianCapitalTerritory.php

@@ -33,7 +33,13 @@ class AustralianCapitalTerritory extends Australia
      */
     public const ID = 'AU-ACT';
 
-    public string $timezone = 'Australia/ACT';
+    /**
+     * This was "Australia/ACT" in the past, which is only a link to Australia/Sydney.
+     * In recent versions of PHP "Australia/ACT" was removed, so this is no longer the link version.
+     *
+     * @see https://en.wikipedia.org/wiki/List_of_tz_database_time_zones
+     */
+    public string $timezone = 'Australia/Sydney';
 
     /**
      * Initialize holidays for Australian Capital Territory (Australia).

src/Yasumi/Provider/Ukraine.php

@@ -48,7 +48,16 @@ class Ukraine extends AbstractProvider
      */
     public function initialize(): void
     {
-        $this->timezone = 'Europe/Kiev';
+        // the name of the timezone changed at some point and some systems support both names,
+        // while others only support the old or the new one -> try out, which version is actually working
+        try {
+            new \DateTimeZone('Europe/Kiev');
+            $this->timezone = 'Europe/Kiev';
+        } catch (\Exception $e) {
+            // this is an DateInvalidTimeZoneException only since 8.3
+            // see https://www.php.net/manual/en/datetimezone.construct.php
+            $this->timezone = 'Europe/Kyiv';
+        }
 
         // Add common holidays
         // New Years Day will not be substituted to an monday if it's on a weekend!