Merge branch '3.4' into 4.4

* 3.4:
  [PropertyAccess] fix tests
  [WebProfilerBundle] fix test
  remove assertions that can never be reached
  [PropertyAccess] Improve message of unitialized property in php 7.4
  [HttpFoundation] Fixed session migration with custom cookie lifetime
  [Serializer] Remove unused variable
  Allow URL-encoded special characters in basic auth part of URLs
  [Serializer] Fix unitialized properties (from PHP 7.4.2) when serializing context for the cache key
  [Validator] Add missing Ukrainian and Russian translations
  No need to reconnect the bags to the session
  Support for Content Security Policy style-src-elem and script-src-elem in WebProfiler
  [PropertyInfo][ReflectionExtractor] Check the array mutator prefixes last when the property is singular

Author: nicolas-grekas

Inline.php

@@ -615,7 +615,7 @@ private static function evaluateScalar(string $scalar, int $flags, array $refere
                             throw new ParseException(sprintf('The constant "%s" is not defined.', $const), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
                         }
                         if (self::$exceptionOnInvalidType) {
-                            throw new ParseException(sprintf('The string "%s" could not be parsed as a constant. Have you forgotten to pass the "Yaml::PARSE_CONSTANT" flag to the parser?', $scalar), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
+                            throw new ParseException(sprintf('The string "%s" could not be parsed as a constant. Did you forget to pass the "Yaml::PARSE_CONSTANT" flag to the parser?', $scalar), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename);
                         }
 
                         return null;