Merge pull request godotengine#101532 from bruvzg/rtl_fix_fx_offset

[RTL] Fix character effect offset.

Author: akien-mga

scene/gui/rich_text_label.cpp

@@ -1222,7 +1222,7 @@ int RichTextLabel::_draw_line(ItemFrame *p_frame, int p_line, const Vector2 &p_o
 								custom_fx_ok = effect_status;
 
 								char_xform = charfx->transform;
-								fx_offset += charfx->offset;
+								fx_offset = charfx->offset;
 								font_color = charfx->color;
 								frid = charfx->font;
 								gl = charfx->glyph_index;