N°5809 Fix compilation error due to CASLogger VS LoggerInterface in psr/log

"Declaration of Combodo\iTop\Cas\CASLogger::emergency($message, array $context = []) must be compatible with Psr\Log\LoggerInterface::emergency(Stringable|string $message, array $context = [])"

psr/log 3.0.0 brings the BC break
Switching to 2.0.0 is nice as it will bring improvements for PHP 8.0+ !
So adding psr/log ^2.0.0 to composer.json

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "d8f21d10c2e9f2f9098698443baa8dd5",
+    "content-hash": "6d27a76ae44c8f09bd214be169536b43",
     "packages": [
         {
             "name": "apereo/phpcas",
@@ -1827,16 +1827,16 @@
         },
         {
             "name": "psr/log",
-            "version": "3.0.0",
+            "version": "2.0.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/php-fig/log.git",
-                "reference": "fe5ea303b0887d5caefd3d431c3e61ad47037001"
+                "reference": "ef29f6d262798707a9edd554e2b82517ef3a9376"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/php-fig/log/zipball/fe5ea303b0887d5caefd3d431c3e61ad47037001",
-                "reference": "fe5ea303b0887d5caefd3d431c3e61ad47037001",
+                "url": "https://api.github.com/repos/php-fig/log/zipball/ef29f6d262798707a9edd554e2b82517ef3a9376",
+                "reference": "ef29f6d262798707a9edd554e2b82517ef3a9376",
                 "shasum": ""
             },
             "require": {
@@ -1845,7 +1845,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.x-dev"
+                    "dev-master": "2.0.x-dev"
                 }
             },
             "autoload": {
@@ -1871,9 +1871,9 @@
                 "psr-3"
             ],
             "support": {
-                "source": "https://github.com/php-fig/log/tree/3.0.0"
+                "source": "https://github.com/php-fig/log/tree/2.0.0"
             },
-            "time": "2021-07-14T16:46:02+00:00"
+            "time": "2021-07-14T16:41:46+00:00"
         },
         {
             "name": "ralouphie/getallheaders",