Exclude first-party stubs from validation

Stub files from vendor directories aren't validated. But the stub
files that ship with PHPstan itself weren't excluded, and they were
hitting the `checkMissingOverrideMethodAttribute` check.

This didn't happen when PHPstan was installed through composer, since
then the stub files happened to be in a vendor directory. But it did
happen when PHPstan ran as a phar.

Resolves phpstan/phpstan#11907.

Author: blyxxyz

src/PhpDoc/DefaultStubFilesProvider.php

@@ -8,8 +8,11 @@
 use PHPStan\Internal\ComposerHelper;
 use function array_filter;
 use function array_values;
+use function dirname;
 use function str_contains;
+use function str_starts_with;
 use function strtr;
+use const DIRECTORY_SEPARATOR;
 
 #[AutowiredService(as: StubFilesProvider::class)]
 final class DefaultStubFilesProvider implements StubFilesProvider
@@ -59,6 +62,10 @@ public function getProjectStubFiles(): array
 		}
 
 		$filteredStubFiles = $this->getStubFiles();
+		$filteredStubFiles = array_filter(
+			$filteredStubFiles,
+			static fn (string $file): bool => !str_starts_with($file, dirname(dirname(__DIR__)) . DIRECTORY_SEPARATOR . 'stubs')
+		);
 		foreach ($this->composerAutoloaderProjectPaths as $composerAutoloaderProjectPath) {
 			$composerConfig = ComposerHelper::getComposerConfig($composerAutoloaderProjectPath);
 			if ($composerConfig === null) {

tests/PHPStan/PhpDoc/DefaultStubFilesProviderTest.php

@@ -4,6 +4,7 @@
 
 use Override;
 use PHPStan\Testing\PHPStanTestCase;
+use function dirname;
 use function sprintf;
 
 class DefaultStubFilesProviderTest extends PHPStanTestCase
@@ -29,10 +30,12 @@ public function testGetStubFiles(): void
 	public function testGetProjectStubFiles(): void
 	{
 		$thirdPartyStubFile = sprintf('%s/vendor/thirdpartyStub.stub', $this->currentWorkingDirectory);
-		$defaultStubFilesProvider = $this->createDefaultStubFilesProvider(['/projectStub.stub', $thirdPartyStubFile]);
+		$firstPartyStubFile = dirname(dirname(dirname(__DIR__))) . DIRECTORY_SEPARATOR . 'stubs' . DIRECTORY_SEPARATOR . 'spl.stub';
+		$defaultStubFilesProvider = $this->createDefaultStubFilesProvider(['/projectStub.stub', $thirdPartyStubFile, $firstPartyStubFile]);
 		$projectStubFiles = $defaultStubFilesProvider->getProjectStubFiles();
 		$this->assertContains('/projectStub.stub', $projectStubFiles);
 		$this->assertNotContains($thirdPartyStubFile, $projectStubFiles);
+		$this->assertNotContains($firstPartyStubFile, $projectStubFiles);
 	}
 
 	public function testGetProjectStubFilesWhenPathContainsWindowsSeparator(): void