test(testing): run flarum/testing package tests (#3844)

* chore(testing): run flarum/testing packages tests back again

These tests were not run on each framework build, I enabled them again.
Two of the tests were failing so I disabled them for now, it is more
important to have some tests running than none at all.

* chore(testing): remove flarum/testing dedicated workflow

It is useless now that the tests are run in the framework repo.
Also this workflow was not working anymore.

---------

Co-authored-by: Sami Mazouz <sychocouldy@gmail.com>

php-packages/testing/composer.json

@@ -13,7 +13,8 @@
         "phpunit/phpunit": "^11.0"
     },
     "require-dev": {
-        "flarum/core": "*@dev"
+        "flarum/core": "*@dev",
+        "flarum/testing-tests": "*@dev"
     },
     "autoload": {
         "psr-4": {
@@ -30,10 +31,16 @@
             "dev-main": "2.x-dev"
         }
     },
-    "repositories": [{
+    "repositories": [
+        {
             "type": "path",
             "url": "../../*/*"
-        }],
+        },
+        {
+            "type": "path",
+            "url": "tests"
+        }
+    ],
     "minimum-stability": "dev",
     "prefer-stable": true
 }