Correctly set path

Author: javiercn

src/StaticWebAssetsSdk/Tasks/DefineStaticWebAssetEndpoints.cs

@@ -276,7 +276,11 @@ private string GetTestFileLength(StaticWebAsset asset)
         private static (string mimeType, string cache) ResolveContentType(StaticWebAsset asset, ContentTypeProvider contentTypeProvider, StaticWebAssetGlobMatcher.MatchContext matchContext, TaskLoggingHelper log)
         {
             var relativePath = asset.ComputePathWithoutTokens(asset.RelativePath);
+#if NET9_0_OR_GREATER
             matchContext.SetPathAndReinitialize(relativePath.AsSpan());
+#else
+            matchContext.SetPathAndReinitialize(relativePath);
+#endif
             var mapping = contentTypeProvider.ResolveContentTypeMapping(matchContext, log);
 
             if (mapping.MimeType != null)