### Godot version

v4.0.stable.official [92bee43ad]

### System information

Steam OS Holo, Steam Deck

### Issue description

Using a `[br]` tag at the end of a line in a documentation comment adds an additional space at the beginning of the following line:

![image](https://user-images.githubusercontent.com/857660/236700815-c78a317f-cdf8-4f3c-8489-41f9559ffe6d.png)


### Steps to reproduce

The script below is what I used to generate the image above:

```gdscript
class_name Test
extends Node

## High-level description
##
## First line of detail.[br]
## Second line of detail.
```

Removing the space between `##` and `Second` doesn't change the output.

The only workaround I've found so far is to remove the linebreak after the `[br]` tag, but this makes the documentation comments harder to read in the editor:

```gdscript
class_name Test
extends Node

## High-level description
##
## First line of detail.[br]Second line of detail.
```

### Minimal reproduction project

N/A
int begin_scan = String("@tutorial").length();
			if (begin_scan >= stripped_line.length()) {
				continue; 
			}
			if (stripped_line[begin_scan] == ':') { 
				
				title = "";
				link = stripped_line.trim_prefix("@tutorial:").strip_edges();
			} else {
				/* Syntax:
				 *   @tutorial ( The Title Here )         :         https://the.url/
				 *             ^ open           ^ close   ^ colon   ^ url
				 */
				int open_bracket_pos = begin_scan, close_bracket_pos = 0;
				while (open_bracket_pos < stripped_line.length() && (stripped_line[open_bracket_pos] == ' ' || stripped_line[open_bracket_pos] == '\t')) {
					open_bracket_pos++;
				}
				if (open_bracket_pos == stripped_line.length() || stripped_line[open_bracket_pos++] != '(') {
					continue; 
				}
				close_bracket_pos = open_bracket_pos;
				while (close_bracket_pos < stripped_line.length() && stripped_line[close_bracket_pos] != ')') {
					close_bracket_pos++;
				}
				if (close_bracket_pos == stripped_line.length()) {
					continue; 
				}
				int colon_pos = close_bracket_pos + 1;
				while (colon_pos < stripped_line.length() && (stripped_line[colon_pos] == ' ' || stripped_line[colon_pos] == '\t')) {
					colon_pos++;