fix return type of LangageServiceHost.resolve*

Fixes: #28058

Author: ajafff

src/services/types.ts

@@ -212,9 +212,9 @@ namespace ts {
          *
          * If this is implemented, `getResolvedModuleWithFailedLookupLocationsFromCache` should be too.
          */
-        resolveModuleNames?(moduleNames: string[], containingFile: string, reusedNames?: string[], redirectedReference?: ResolvedProjectReference): ResolvedModule[];
+        resolveModuleNames?(moduleNames: string[], containingFile: string, reusedNames?: string[], redirectedReference?: ResolvedProjectReference): (ResolvedModule | undefined)[];
         getResolvedModuleWithFailedLookupLocationsFromCache?(modulename: string, containingFile: string): ResolvedModuleWithFailedLookupLocations | undefined;
-        resolveTypeReferenceDirectives?(typeDirectiveNames: string[], containingFile: string, redirectedReference?: ResolvedProjectReference): ResolvedTypeReferenceDirective[];
+        resolveTypeReferenceDirectives?(typeDirectiveNames: string[], containingFile: string, redirectedReference?: ResolvedProjectReference): (ResolvedTypeReferenceDirective | undefined)[];
         /* @internal */ hasInvalidatedResolution?: HasInvalidatedResolution;
         /* @internal */ hasChangedAutomaticTypeDirectiveNames?: boolean;