chore(CI): use nightly rust

.github/workflows/compiler_benchmark.yml

@@ -86,7 +86,7 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
           override: true
 
       - name: Build compiler benchmarks

.github/workflows/compiler_build_and_test_gpu.yml

@@ -66,7 +66,7 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
           override: true
 
       - name: Create build dir

.github/workflows/compiler_macos_build_and_test.yml

@@ -31,7 +31,8 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
+          override: true
 
       - name: Install Deps
         run: |

.github/workflows/concrete_cpu_test.yml

@@ -21,7 +21,9 @@ jobs:
       - name: Rust install
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
+          override: true
+          components: rustfmt, clippy
 
       - name: Download cargo cache
         uses: Swatinem/rust-cache@v2
@@ -54,7 +56,7 @@ jobs:
       - name: Tests
         run: |
           cd backends/concrete-cpu
-          cargo test --no-fail-fast --all-targets
+          cargo test --no-fail-fast --all-targets --features=nightly
 
       - name: Zig install
         run: |
@@ -75,7 +77,8 @@ jobs:
       - name: Rust install
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
+          override: true
 
       - name: Download cargo cache
         uses: Swatinem/rust-cache@v2

.github/workflows/ml_benchmark_subset.yml

@@ -66,7 +66,7 @@ jobs:
       - name: Install rust
         uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: nightly
           override: true
 
       - name: Build compiler and ML benchmarks