Skip incremental scenario diffs on doc builds

Incremental isn't supported with rustdoc so these end up failing on trying to
find the relevant files.

Author: Mark-Simulacrum

collector/src/main.rs

@@ -88,6 +88,15 @@ impl ScenarioKind {
         vec![ScenarioKind::Full]
     }
 
+    fn is_incr(self) -> bool {
+        match self {
+            ScenarioKind::Full => false,
+            ScenarioKind::IncrFull | ScenarioKind::IncrUnchanged | ScenarioKind::IncrPatched => {
+                true
+            }
+        }
+    }
+
     fn default() -> Vec<ScenarioKind> {
         Self::all()
     }
@@ -501,6 +510,9 @@ fn generate_cachegrind_diffs(
                 if let ScenarioKind::IncrPatched = scenario_kind {
                     continue;
                 }
+                if build_kind == BuildKind::Doc && scenario_kind.is_incr() {
+                    continue;
+                }
                 let filename = |prefix, id| {
                     format!(
                         "{}-{}-{}-{:?}-{:?}",