PHPLIB-1119: Update to Psalm 5 (#1131)

* Update to psalm 5

* Enable reporting about unused baseline entries

* Remove dangerous instantiation

Instantiating static in non-final classes makes assumptions about child class constructors, which is unsafe.

* Fix missing return types

* Fix more psalm errors

Author: alcaeus

source/examples/csfle-explicit_encryption.php

@@ -41,6 +41,8 @@
 
 /* Using the client configured without encryption, find the document and observe
  * that the field is not automatically decrypted. */
+
+/** @var object{encryptedField: Binary} $document */
 $document = $collection->findOne();
 
 print_r($document);