memory usage improvements

Cargo.lock

@@ -289,8 +289,6 @@ dependencies = [
  "pathdiff",
  "prettytable-rs",
  "rayon",
- "serde",
- "serde_json",
  "threadpool",
  "unicode-segmentation",
 ]
@@ -750,17 +748,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "serde_json"
-version = "1.0.120"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e0d21c9a8cae1235ad58a00c11cb40d4b1e5c784f1ef2c537876ed6ffd8b7c5"
-dependencies = [
- "itoa",
- "ryu",
- "serde",
-]
-
 [[package]]
 name = "smallvec"
 version = "1.13.2"