No chunks returned because of "No content extracted"

### Bug

While giving a particular URL to v1/chunk/hybrid/source/async i receive this:

```
"chunks": [],
"documents": [
{
"kind": "ExportResult",
"content": {
"filename": "example",
"md_content": null,
"json_content": {
"schema_name": "DoclingDocument",
"version": "1.7.0",
"name": "example",
"origin": {
"mimetype": "text/html",
"binary_hash": 545364923*****,
"filename": "example",
"uri": null
},
"furniture": {
"self_ref": "#/furniture",
"parent": null,
"children": [],
"content_layer": "furniture",
"name": "_root_",
"label": "unspecified"
},
"body": {
"self_ref": "#/body",
"parent": null,
"children": [
{
"$ref": "#/texts/0"
},
{
"$ref": "#/texts/1"
},
{
"$ref": "#/texts/2"
},
{
"$ref": "#/texts/3"
},
{ .....
```
Unfortunately because of privacy reasons i can't give you the url but i'll do my best to describe and give snippets of the code.

docling in the documents returns the whole content of the page and all the text in it so it's not a javacript rendering problem. it's a pretty long page but even when setting a very high max_token param i still get the same issue.

The html of the page contains a very long list of elements, here is an example:

```
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