Rollup merge of #56516 - frewsxcv:frewsxcv-eq, r=Mark-Simulacrum

Replace usages of `..i + 1` ranges with `..=i`.

Before this change we were using old computer code techniques. After this change we use the new and improved computer code techniques.

src/librustdoc/html/render.rs

@@ -4798,7 +4798,7 @@ impl<'a> fmt::Display for Source<'a> {
             tmp /= 10;
         }
         write!(fmt, "<pre class=\"line-numbers\">")?;
-        for i in 1..lines + 1 {
+        for i in 1..=lines {
             write!(fmt, "<span id=\"{0}\">{0:1$}</span>\n", i, cols)?;
         }
         write!(fmt, "</pre>")?;