[rust] Make CI fail on warnings (#6763)

https://doc.rust-lang.org/stable/clippy/continuous_integration/github_actions.html

.github/workflows/rust-lint.yml

@@ -15,6 +15,9 @@ concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}
     cancel-in-progress: true
 
+env:
+    RUSTFLAGS: -D warnings
+
 jobs:
     lint:
         runs-on: ubuntu-latest
@@ -33,9 +36,9 @@ jobs:
                       ~/.cargo/git
                       target
                   key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
-                            
+
             - run: cargo fmt --check
 
-            - run: cargo clippy
+            - run: cargo clippy --all-targets --all-features
 
             - run: cargo build