Allow specifying MAX_EXCERPTS via an env variable in random tests

crates/editor/src/display_map.rs

@@ -532,7 +532,7 @@ mod tests {
                 let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
                 MultiBuffer::build_simple(&text, cx)
             } else {
-                MultiBuffer::build_random(rng.gen_range(1..=5), &mut rng, cx)
+                MultiBuffer::build_random(&mut rng, cx)
             }
         });