chore: bump Rust toolchain from 1.91.0 to 1.94.0 (#3257)

Bumps the Rust toolchain to 1.94.0 (latest installed) to unblock CI
failures caused by the AWS SDK's MSRV requirement. No lint fixes were
needed.

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/nodejs.yml

@@ -8,6 +8,7 @@ on:
     paths:
       - Cargo.toml
       - Cargo.lock
+      - rust-toolchain.toml
       - nodejs/**
       - rust/**
       - docs/src/js/**

.github/workflows/python.yml

@@ -8,6 +8,7 @@ on:
     paths:
       - Cargo.toml
       - Cargo.lock
+      - rust-toolchain.toml
       - python/**
       - rust/**
       - .github/workflows/python.yml

.github/workflows/rust.yml

@@ -8,6 +8,7 @@ on:
     paths:
       - Cargo.toml
       - Cargo.lock
+      - rust-toolchain.toml
       - rust/**
       - .github/workflows/rust.yml
 

rust-toolchain.toml

@@ -1,2 +1,2 @@
 [toolchain]
-channel = "1.91.0"
+channel = "1.94.0"

rust/lancedb/src/embeddings/bedrock.rs

@@ -177,6 +177,7 @@ impl BedrockEmbeddingFunction {
                         ))
                         .send()
                         .await
+                        .map_err(Box::new)
                 })
             })
             .unwrap();