Fix cargo clippy issues 0.1.65 in Rust (#923)

# Description
- Fix the latest cargo clippy issues in Rust from the version `0.1.65`

Author: fvaleye

.github/workflows/build.yml

@@ -39,7 +39,7 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           profile: default
-          toolchain: stable
+          toolchain: "1.64.0" # Switch to "stable" when the 1.67.0 release of https://github.com/rust-lang/rust is published, more information: https://github.com/delta-io/delta-rs/pull/923
           override: true
       - uses: Swatinem/rust-cache@v1
       - name: build and lint with clippy
@@ -64,7 +64,7 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           profile: default
-          toolchain: stable
+          toolchain: "1.64.0" # Switch to "stable" when the 1.67.0 release of https://github.com/rust-lang/rust is published, more information: https://github.com/delta-io/delta-rs/pull/923
           override: true
       - uses: Swatinem/rust-cache@v1
       - name: Run tests