Disable async-openai feature of tiktoken-rs crate

We don't make use of this feature, so it's not necessary.

Ref: af52be12fa/tiktoken-rs/Cargo.toml (L21)

Cargo.lock

@@ -192,38 +192,6 @@ dependencies = [
  "tokio",
 ]
 
-[[package]]
-name = "async-convert"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d416feee97712e43152cd42874de162b8f9b77295b1c85e5d92725cc8310bae"
-dependencies = [
- "async-trait",
-]
-
-[[package]]
-name = "async-openai"
-version = "0.14.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e1df052c2bd7b241fc828bc2fda74ce9a7ef05e0a593c37275aaaba52caf49d"
-dependencies = [
- "async-convert",
- "backoff",
- "base64 0.21.7",
- "derive_builder 0.12.0",
- "futures",
- "rand 0.8.5",
- "reqwest 0.11.27",
- "reqwest-eventsource 0.4.0",
- "serde",
- "serde_json",
- "thiserror 1.0.69",
- "tokio",
- "tokio-stream",
- "tokio-util",
- "tracing",
-]
-
 [[package]]
 name = "async-openai"
 version = "0.28.1"
@@ -350,7 +318,7 @@ version = "1.7.2"
 dependencies = [
  "anthropic",
  "anyhow",
- "async-openai 0.28.1",
+ "async-openai",
  "base64 0.22.1",
  "chrono",
  "etke_openai_api_rust",
@@ -3106,7 +3074,6 @@ dependencies = [
  "js-sys",
  "log",
  "mime",
- "mime_guess",
  "once_cell",
  "percent-encoding",
  "pin-project-lite",
@@ -4039,7 +4006,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "25563eeba904d770acf527e8b370fe9a5547bacd20ff84a0b6c3bc41288e5625"
 dependencies = [
  "anyhow",
- "async-openai 0.14.3",
  "base64 0.22.1",
  "bstr",
  "fancy-regex",