Replace lazy_static with OnceLock

This commit replaces the `lazy_static` crate with `std::sync::OnceLock`.
This removes an external dependency and utilizes a standard library
feature for lazy initialization.

Additionally, a benchmark regression test has been added to
`src/ast/tester.rs`.

Cargo.lock

@@ -1731,12 +1731,6 @@ version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2db585e1d738fc771bf08a151420d3ed193d9d895a36df7f6f8a9456b911ddc"
 
-[[package]]
-name = "lazy_static"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
-
 [[package]]
 name = "leb128fmt"
 version = "0.1.0"
@@ -1890,7 +1884,6 @@ dependencies = [
  "chrono",
  "clap",
  "eframe",
- "lazy_static",
  "regex",
 ]