prepare release 1.26.0 (#3554)

* bump version
* suppress deprecation
* composer update to fix twig security issue
* make sure to use the same timezone in all test runs

src/Constants.php

@@ -17,11 +17,11 @@ class Constants
     /**
      * The current release version
      */
-    public const VERSION = '1.25.0';
+    public const VERSION = '1.26.0';
     /**
      * The current release: major * 10000 + minor * 100 + patch
      */
-    public const VERSION_ID = 12500;
+    public const VERSION_ID = 12600;
     /**
      * The current release status, either "stable" or "dev"
      */