Clean up dependencies of mdbook

These are no longer used, or are dev-dependencies only.

Cargo.lock

@@ -1273,18 +1273,14 @@ dependencies = [
  "mdbook-preprocessor",
  "mdbook-renderer",
  "mdbook-summary",
- "memchr",
  "notify",
  "notify-debouncer-mini",
  "opener",
  "pathdiff",
- "pulldown-cmark 0.10.3",
  "regex",
  "select",
  "semver",
- "serde",
  "serde_json",
- "shlex",
  "snapbox",
  "tempfile",
  "tokio",

Cargo.toml

@@ -78,14 +78,7 @@ mdbook-markdown.workspace = true
 mdbook-preprocessor.workspace = true
 mdbook-renderer.workspace = true
 mdbook-summary.workspace = true
-memchr.workspace = true
 opener = "0.8.1"
-pulldown-cmark.workspace = true
-regex.workspace = true
-serde.workspace = true
-serde_json.workspace = true
-shlex.workspace = true
-tempfile.workspace = true
 toml.workspace = true
 
 # Watch feature
@@ -102,9 +95,12 @@ axum = { version = "0.8.0", features = ["ws"], optional = true }
 tower-http = { version = "0.6.0", features = ["fs", "trace"], optional = true }
 
 [dev-dependencies]
+regex.workspace = true
 select = "0.6.0"
 semver = "1.0.17"
+serde_json.workspace = true
 snapbox = { version = "0.6.21", features = ["diff", "dir", "term-svg", "regex", "json"] }
+tempfile.workspace = true
 walkdir = "2.3.3"
 
 [features]