Calculates post length incorrectly

[jikamens]

Detailed description

When I go to edit the current version of https://federate.social/@jik/112391392864473951 in the Mastodon web app, it says I have one free character. When I go to edit exactly the same post in Tusky Test 25.0-ad1afdd2, it says the post is 71 characters too long immediately when I start editing it.

My Mastodon server is running version 4.2.8.

Steps to reproduce the problem

1. Edit a post. I suspect the problem is the links, but that's just a guess, so edit a post with links.
2. Observe how the length shown in Tusky is different from the length shown when you edit the post in the Mastodon web app.

Debug information

Tusky Test 25.0-ad1afdd2
Google Pixel 8
Android version: 14
SDK version: 34