[13.x] Fix DumpCommand return type.

[KentarouTakeda]

This PR changes DumpCommand::handle() to return Command::SUCCESS on success and updates its DocBlock from @return void to @return int.

Since the method already returned Command::FAILURE in some cases, the previous @return void annotation was incorrect. No native return type has been added, so this introduces no breaking change.

We encountered this while overriding DumpCommand in our project. The incorrect DocBlock causes PHPStan to report an incompatible method signature, and this change resolves that inconsistency.

[shaedrich]

You could narrow this further down:

Suggested change

	* @return int
	* @return self::SUCCESS|self::FAILURE|self::INVALID

[KentarouTakeda]

Thanks, but I'd rather keep @return int here: handle() never returns INVALID, so that union would be inaccurate. And narrowing it further would introduce a new incompatible-signature error for subclasses that return any other exit code.

[shaedrich]

How is int not inaccurate if self::INVALID is? That logic escapes me.

[KentarouTakeda]

Fair — sloppy wording; int is wider than what this method returns today, but not wider than what's allowed. Command::execute() casts whatever handle() returns with (int) and passes it straight through, and Symfony only caps it at 255 — the framework itself already emits other codes via --isolated=<n>. So int is the contract, and the union would document a constraint that isn't there.

[lucasmichot]

Suggested change

	return Command::SUCCESS;
	return self::SUCCESS;

[KentarouTakeda]

Thanks! Every command under Database/Console uses Command::, including the Command::FAILURE a few lines above in this same method, so I'll keep it consistent.