Bump symfony/event-dispatcher from 3.4.43 to 3.4.44

Bumps [symfony/event-dispatcher](https://github.com/symfony/event-dispatcher) from 3.4.43 to 3.4.44.
- [Release notes](https://github.com/symfony/event-dispatcher/releases)
- [Changelog](https://github.com/symfony/event-dispatcher/blob/master/CHANGELOG.md)
- [Commits](https://github.com/symfony/event-dispatcher/compare/v3.4.43...v3.4.44)

Signed-off-by: dependabot[bot] <support@github.com>

composer.lock

@@ -440,16 +440,16 @@
         },
         {
             "name": "symfony/event-dispatcher",
-            "version": "v3.4.43",
+            "version": "v3.4.44",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/event-dispatcher.git",
-                "reference": "14d978f8e8555f2de719c00eb65376be7d2e9081"
+                "reference": "a0f6858fbf7a524747e87a4c336cab7d0b67c802"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/event-dispatcher/zipball/14d978f8e8555f2de719c00eb65376be7d2e9081",
-                "reference": "14d978f8e8555f2de719c00eb65376be7d2e9081",
+                "url": "https://api.github.com/repos/symfony/event-dispatcher/zipball/a0f6858fbf7a524747e87a4c336cab7d0b67c802",
+                "reference": "a0f6858fbf7a524747e87a4c336cab7d0b67c802",
                 "shasum": ""
             },
             "require": {
@@ -513,7 +513,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2020-05-05T15:06:23+00:00"
+            "time": "2020-08-12T14:55:37+00:00"
         },
         {
             "name": "symfony/filesystem",