fix: use 'target' (singular) for setup-rust-toolchain action input

The actions-rust-lang/setup-rust-toolchain action expects 'target' not
'targets'. The typo caused wasm32-wasip1 to not be installed, failing
the WASM guard build in the release workflow.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lpcox

.github/workflows/release.lock.yml

@@ -279,7 +279,7 @@ jobs:
       - name: Set up Rust
         uses: actions-rust-lang/setup-rust-toolchain@a0b538fa0b742a6aa35d6e2c169b4bd06d225a98 # v1.15.3
         with:
-          targets: wasm32-wasip1
+          target: wasm32-wasip1
 
       - name: Build baked WASM guard
         run: |