Increase max line width slightly

This is needed to render some new in-code documentation correctly

rustfmt.toml

@@ -7,6 +7,6 @@ use_field_init_shorthand = true
 use_try_shorthand = true
 format_code_in_doc_comments = true
 wrap_comments = true
-max_width = 110
-comment_width = 110
+max_width = 115
+comment_width = 115
 use_small_heuristics = "max"