### Godot version

v4.1.beta.custom_build [ea6a141ff]

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

I noticed editor log misbehaving when a text is being printed. It seems to be mostly noticeable (or exclusive to?) when collapsing of duplicate messages is enabled.

https://github.com/godotengine/godot/assets/2223172/4ccfaa70-8991-4f5d-95ec-c732600b82ec

It looks like the log rebuilds from scratch with every message. If it had already some content, the text might be printed faster than it appears, causing it to be unreadable:

https://github.com/godotengine/godot/assets/2223172/6b69d308-37f1-4d8f-b47c-09f2e42eda43


### Steps to reproduce

```GDScript
func _process(delta: float) -> void:
	print("spam")
```

### Minimal reproduction project

N/A
_stop_thread();
	MutexLock data_lock(data_mutex);
	ERR_FAIL_COND(current->type == ITEM_TABLE);
	ItemStrikethrough *item = memnew(ItemStrikethrough);
	_add_item(item, true);
}
void RichTextLabel::push_paragraph(HorizontalAlignment p_alignment, Control::TextDirection p_direction, const String &p_language, TextServer::StructuredTextParser p_st_parser, BitField<TextServer::JustificationFlag> p_jst_flags, const PackedFloat32Array &p_tab_stops) {
	_stop_thread();
	MutexLock data_lock(data_mutex);
	ERR_FAIL_COND(current->type == ITEM_TABLE);
	ItemParagraph *item = memnew(ItemParagraph);
	item->alignment = p_alignment;
	item->direction = p_direction;
	item->language = p_language;
	item->st_parser = p_st_parser;
	item->jst_flags = p_jst_flags;
	item->tab_stops = p_tab_stops;
	_add_item(item, true, true);
}
void RichTextLabel::push_indent(int p_level) {
	_stop_thread();
	MutexLock data_lock(data_mutex);
	ERR_FAIL_COND(current->type == ITEM_TABLE);
	ERR_FAIL_COND(p_level < 0);
	ItemIndent *item = memnew(ItemIndent);
	item->level = p_level;
	_add_item(item, true, true);
}
void RichTextLabel::push_list(int p_level, ListType p_list, bool p_capitalize, const String &p_bullet) {