### Godot version

v4.1.stable.official [970459615]

### System information

Godot v4.1.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce MX330 (NVIDIA; 30.0.15.1169) - 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz (8 Threads)

### Issue description

Calling `RichTextLabel`'s `select_all` method has no visual indicator, but it must have one. 

### Steps to reproduce

- Add `RichTextLabel` node
- Set `selection_enabled` value to be `true`
- Call `$RichTextLabel.select_all() `method in `_ready`

### Minimal reproduction project

[RichTextLabel_bug.zip](https://github.com/godotengine/godot/files/12098913/RichTextLabel_bug.zip)

uint32_t gl = glyphs[i].index;
			uint16_t gl_fl = glyphs[i].flags;
			uint8_t gl_cn = glyphs[i].count;
			bool cprev_cluster = false;
			bool cprev_conn = false;
			if (gl_cn == 0) { 
				cprev_cluster = true;
			}
			if (gl_fl & TextServer::GRAPHEME_IS_RTL) { 
				if (i > 0 && (glyphs[i - 1].flags & TextServer::GRAPHEME_IS_CONNECTED)) {
					cprev_conn = true;
				}
			} else {
				if (glyphs[i].flags & TextServer::GRAPHEME_IS_CONNECTED) {
					cprev_conn = true;
				}
			}
			
			if (fade) {
				float faded_visibility = 1.0f;
				if (glyphs[i].start >= fade->starting_index) {
					faded_visibility -= (float)(glyphs[i].start - fade->starting_index) / (float)fade->length;
					faded_visibility = faded_visibility < 0.0f ? 0.0f : faded_visibility;
				}
				font_outline_color.a = faded_visibility;
				font_shadow_color.a = faded_visibility;
			}
			bool txt_visible = (font_outline_color.a != 0) || (font_shadow_color.a != 0);
			for (int j = 0; j < fx_stack.size(); j++) {
				ItemFX *item_fx = fx_stack[j];