Fix PHPStan issues for src/Serializer/*

All bundled in one commit to not flood the history, all of these should
be trivial on itself but help PHPStan to detect more issues.

Key,value with only strings as: public const POST_SERIALIZE = 'serializer.post_serialize'

Author: vmcj

phpstan-baseline.neon

@@ -390,36 +390,6 @@ parameters:
 			count: 1
 			path: webapp/src/Helpers/OrdinalArray.php
 
-		-
-			message: "#^Method App\\\\Serializer\\\\ContestProblemVisitor\\:\\:getSubscribedEvents\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: webapp/src/Serializer/ContestProblemVisitor.php
-
-		-
-			message: "#^Method App\\\\Serializer\\\\ContestVisitor\\:\\:getSubscribedEvents\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: webapp/src/Serializer/ContestVisitor.php
-
-		-
-			message: "#^Method App\\\\Serializer\\\\SetExternalIdVisitor\\:\\:getSubscribedEvents\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: webapp/src/Serializer/SetExternalIdVisitor.php
-
-		-
-			message: "#^Method App\\\\Serializer\\\\SubmissionVisitor\\:\\:getSubscribedEvents\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: webapp/src/Serializer/SubmissionVisitor.php
-
-		-
-			message: "#^Method App\\\\Serializer\\\\TeamAffiliationVisitor\\:\\:getSubscribedEvents\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: webapp/src/Serializer/TeamAffiliationVisitor.php
-
-		-
-			message: "#^Method App\\\\Serializer\\\\TeamVisitor\\:\\:getSubscribedEvents\\(\\) return type has no value type specified in iterable type array\\.$#"
-			count: 1
-			path: webapp/src/Serializer/TeamVisitor.php
-
 		-
 			message: "#^Method App\\\\Service\\\\AwardService\\:\\:getAwards\\(\\) return type has no value type specified in iterable type array\\.$#"
 			count: 1

webapp/src/Serializer/ContestProblemVisitor.php

@@ -19,6 +19,9 @@ public function __construct(
         protected readonly EventLogService $eventLogService
     ) {}
 
+    /**
+     * @return array<array{event: string, class: string, format: string, method: string}>
+     */
     public static function getSubscribedEvents(): array
     {
         return [

webapp/src/Serializer/ContestVisitor.php

@@ -21,6 +21,9 @@ public function __construct(
         protected readonly EventLogService $eventLogService
     ) {}
 
+    /**
+     * @return array<array{event: string, class: string, format: string, method: string}>
+     */
     public static function getSubscribedEvents(): array
     {
         return [

webapp/src/Serializer/SetExternalIdVisitor.php

@@ -19,6 +19,9 @@ public function __construct(protected readonly EventLogService $eventLogService)
     {
     }
 
+    /**
+     * @return array<array{event: string, format: string, method: string}>
+     */
     public static function getSubscribedEvents(): array
     {
         return [

webapp/src/Serializer/SubmissionVisitor.php

@@ -20,6 +20,9 @@ public function __construct(
         protected readonly EntityManagerInterface $em
     ) {}
 
+    /**
+     * @return array<array{event: string, class: string, format: string, method: string}>
+     */
     public static function getSubscribedEvents(): array
     {
         return [

webapp/src/Serializer/TeamAffiliationVisitor.php

@@ -24,6 +24,9 @@ public function __construct(
         protected readonly RequestStack $requestStack
     ) {}
 
+    /**
+     * @return array<array{event: string, class: string, format: string, method: string}>
+     */
     public static function getSubscribedEvents(): array
     {
         return [

webapp/src/Serializer/TeamVisitor.php

@@ -21,6 +21,9 @@ public function __construct(
         protected readonly RequestStack $requestStack
     ) {}
 
+    /**
+     * @return array<array{event: string, class: string, format: string, method: string}>
+     */
     public static function getSubscribedEvents(): array
     {
         return [