style: gofumpt all the things (#9829)

Literally `gofumpt -w .` from the top level dir. Guaranteed to be minor
style changes only and nothing else.

@imsodin per request?

test/parallel_scan_test.go

@@ -31,7 +31,7 @@ func TestRescanInParallel(t *testing.T) {
 	}
 
 	log.Println("Generating .stignore...")
-	err = os.WriteFile("s1/.stignore", []byte("some ignore data\n"), 0644)
+	err = os.WriteFile("s1/.stignore", []byte("some ignore data\n"), 0o644)
 	if err != nil {
 		t.Fatal(err)
 	}