Use specific Rust version for workflows to prevent compilation issues with newer versions

.github/workflows/bench.yaml

@@ -21,7 +21,7 @@ jobs:
       - name: Set up Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.39.0
           profile: minimal
           default: true
       - name: Set up Node.js module

.github/workflows/cli.yml

@@ -37,7 +37,7 @@ jobs:
       - name: Set up Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.39.0
           profile: minimal
           default: true
       - name: Build CLI

.github/workflows/java.yml

@@ -26,7 +26,7 @@ jobs:
       - name: Set up Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.39.0
           profile: minimal
           default: true
       - name: Build Java native library

.github/workflows/nodejs.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Set up Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.39.0
           profile: minimal
           default: true
       - name: Build native module

.github/workflows/ruby.yml

@@ -60,7 +60,7 @@ jobs:
       - name: Set up Rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.39.0
           profile: minimal
           default: true
       - name: Build Ruby native library