False positive PSR1.Files.SideEffects.FoundWithSymbols when using php8 attribute

[dakorpar]

Describe the bug
Simple attribute class gives warning

Code sample

<?php declare(strict_types = 1);

namespace My\Namespace;

#[\Attribute]
class Cached
{

}

Custom ruleset

<?xml version="1.0"?>
<ruleset name="My Custom Standard">
  <description>If you are using a custom ruleset, please enter it here.</description>
 <rule ref="PSR1.Files.SideEffects.FoundWithSymbols"></rule
</ruleset>

To reproduce
Steps to reproduce the behavior:
3. See error message displayed

FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
----------------------------------------------------------------------
 1 | WARNING | A file should declare new symbols (classes, functions,
   |         | constants, etc.) and cause no other side effects, or
   |         | it should execute logic with side effects, but should
   |         | not do both. The first symbol is defined on line 6 and
   |         | the first side effect is on line 5.

Expected behavior

Versions (please complete the following information):

• OS: [e.g., Windows 10, MacOS 10.15]
• PHP: [8.0]
• PHPCS: [dev-master]
• Standard: [PSR1]

[jrfnl]

As per #3182 and #3203, attributes are not yet supported in PHPCS, not even in dev-master. Testing of #3203 could help move it forward, but without that PR (or an iteration of it) being merged, it won't be possible to start making sniffs compatible with attributes yet.

[gsherwood]

Now that attribute support has been merged, I've updated this sniff to ignore attributes, which fixes this problem. Thanks for reporting it.