fix generates different html content for the same markdown when get the cached token

[Kalmaegi]

fix generates different html content for the same markdown when get the cached token

This PR fixes #

Hi,I found start from the second time calling render, the id for the Introduction will appended by a number:

Markdown:

[abc](#abc)
# abc

first calling after is correct:

<h1 data-line="4" class="code-line" id="abc">abc</h1>

but second calling after, an error is beginning to occur:

<h1 data-line="4" class="code-line" id="abc-1">abc</h1>

Steps to Reproduce:

1. Click the "Open preview to the side" button
2. Switch back to md
3. Click the "Open preview to the side" button again, and Click on the link titled "abc". The expected behavior is for the preview window to scroll down to the header titled "abc". It does not.

i fond this pr :#47537
so the number is to resolve differentiate same header, but In the case of a hit cache, it's wrong

i find other pr:f732547#diff-0cd672777508d358387063c50187200e7192fdd34946ae7c5a02b5430935d253
look like the same thing

[mjbvz]

Thanks!