### 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
Item *_get_prev_item(Item *p_item, bool p_free = false) const;
	Rect2 _get_text_rect();
	Ref<RichTextEffect> _get_custom_effect_by_code(String p_bbcode_identifier);
	virtual Dictionary parse_expressions_for_values(Vector<String> p_expressions);
	void _draw_fbg_boxes(RID p_ci, RID p_rid, Vector2 line_off, Item *it_from, Item *it_to, int start, int end, int fbg_flag);
#ifndef DISABLE_DEPRECATED
	// 
	bool _set(const StringName &p_name, const Variant &p_value);
#endif
	bool use_bbcode = false;
	String text;
	void _apply_translation();
	bool fit_content = false;
	struct ThemeCache {
		Ref<StyleBox> normal_style;
		Ref<StyleBox> focus_style;
		Ref<StyleBox> progress_bg_style;
		Ref<StyleBox> progress_fg_style;
		int line_separation;
		Ref<Font> normal_font;
		int normal_font_size;
		Color default_color;
		Color font_selected_color;
		Color selection_color;
		Color font_outline_color;
		Color font_shadow_color;
		int shadow_outline_size;
		int shadow_offset_x;
		int shadow_offset_y;
		int outline_size;