Add support for InputInterface::getOption('x'|'y'|'z')

[Seldaek]

When you pass a variable getOption($optName) and $optName is a set of multiple string literals, it should still be possible to resolve the type(s).

It seems fairly easy to tweak

phpstan-symfony/src/Type/Symfony/InputInterfaceGetOptionDynamicReturnTypeExtension.php

Lines 56 to 85 in 7953474

	$optStrings = TypeUtils::getConstantStrings($scope->getType($methodCall->getArgs()[0]->value));
	if (count($optStrings) !== 1) {
	return $defaultReturnType;
	}
	$optName = $optStrings[0]->getValue();
	$optTypes = [];
	foreach ($this->consoleApplicationResolver->findCommands($classReflection) as $command) {
	try {
	$command->mergeApplicationDefinition();
	$option = $command->getDefinition()->getOption($optName);
	if (!$option->acceptValue()) {
	$optType = new BooleanType();
	} else {
	$optType = TypeCombinator::union(new StringType(), new NullType());
	if ($option->isValueRequired() && ($option->isArray() || $option->getDefault() !== null)) {
	$optType = TypeCombinator::removeNull($optType);
	}
	if ($option->isArray()) {
	$optType = new ArrayType(new IntegerType(), $optType);
	}
	$optType = TypeCombinator::union($optType, $scope->getTypeFromValue($option->getDefault()));
	}
	$optTypes[] = $optType;
	} catch (InvalidArgumentException $e) {
	// noop
	}
	}
	return count($optTypes) > 0 ? TypeCombinator::union(...$optTypes) : $defaultReturnType;

to do a loop and concat all the different types instead of returning early a mixed here.

I may try to do this one day, but tonight no time so adding a note here.