Update phpstan/phpstan requirement from ^1.10.21 to ^2.0.0 (#23)

Updates the requirements on [phpstan/phpstan](https://github.com/phpstan/phpstan) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/2.0.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.10.21...2.0.0)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

composer.json

@@ -19,7 +19,7 @@
   },
   "require-dev": {
     "doctrine/coding-standard": "^12.0",
-    "phpstan/phpstan": "^1.10.21"
+    "phpstan/phpstan": "^2.0.0"
   },
   "autoload": {
     "psr-4": {

src/Handler/DataDogUdpHandler.php

@@ -24,13 +24,13 @@
 use function function_exists;
 use function gethostname;
 use function implode;
-use function is_array;
 use function json_encode;
 use function socket_close;
 use function socket_create;
 use function socket_sendto;
 use function strlen;
 use function strtolower;
+use function strval;
 use function substr;
 
 use const AF_INET;
@@ -116,13 +116,12 @@ protected function write(LogRecord $record): void
     private function doWrite(LogRecord $record, Span $span): void
     {
         $tags  = $span->getAllTags();
+        $tags  = array_filter($tags, 'is_scalar');
         $tags += array_filter($record->context, 'is_scalar');
 
-        if (is_array($tags)) {
-            $tags = implode(', ', array_map(static function ($key, $value) {
-                return $key . ':' . $value;
-            }, array_keys($tags), $tags));
-        }
+        $tags = implode(', ', array_map(static function ($key, $value) {
+            return strval($key) . ':' . strval($value);
+        }, array_keys($tags), $tags));
 
         $log = [
             'service' => $span->getService(),