Fix psalm issues

Author: cspray

src/DocBlockArchitecturalDecision.php

@@ -19,7 +19,7 @@ final public function getContents() : string {
             $reflection = new \ReflectionClass(static::class);
             $content = $reflection->getDocComment();
 
-            if (!$content) {
+            if ($content === false) {
                 throw MissingDocBlock::fromClass($reflection->getName());
             }
 

src/XmlDocumentGenerator.php

@@ -74,12 +74,11 @@ public function generateDocument(string $file, array $scanDirs) : void {
                 $dom->createElementNS(ArchitecturalDecisionRecord::SCHEMA, 'contents')
             );
 
-            assert(!is_null($contentsNode->ownerDocument));
             $contentsNode->appendChild(
                 $contentsNode->ownerDocument->createCDATASection($attribute->getContents())
             );
 
-            if (!empty($decisionAnnotation['targets'])) {
+            if ($decisionAnnotation['targets'] !== []) {
                 $codeAnnotationsNode = $decisionElement->appendChild(
                     $dom->createElementNS(ArchitecturalDecisionRecord::SCHEMA, 'codeAnnotations')
                 );

tests/Stub/Adr/StubMetaDataArchitecturalDecision.php

@@ -22,7 +22,6 @@ public function getStatus() : string|DecisionStatus {
 
     public function setMetaData(DOMElement $meta) : void {
         $dom = $meta->ownerDocument;
-        assert(isset($dom));
 
         $foo = $meta->appendChild(
             $dom->createElement('foo')