refactor: non-null packageName (#20485)

lib/modules/manager/swift/extract.ts

@@ -154,6 +154,10 @@ export function extractPackageFile(content: string): PackageFileContent | null {
   let currentValue: string | null = null;
 
   function yieldDep(): void {
+    // istanbul ignore if
+    if (!packageName) {
+      return;
+    }
     const depName = getDepName(packageName);
     if (depName && currentValue) {
       const dep: PackageDependency = {

lib/modules/manager/types.ts

@@ -110,7 +110,7 @@ export interface PackageDependency<T = Record<string, any>>
   fileReplacePosition?: number;
   groupName?: string;
   lineNumber?: number;
-  packageName?: string | null;
+  packageName?: string;
   target?: string;
   versioning?: string;
   dataType?: string;