Use dtolnay/rust-toolchain@master instead of @stable

This allows passing the `toolchain` input.

Changes.md

@@ -1,3 +1,8 @@
+## 0.0.5 - 2023-03-19
+
+- Fix use of `dtolnay/rust-toolchain` action to allow passing a `toolchain`
+  input.
+
 ## 0.0.4 - 2023-03-19
 
 - Added a new `toolchain` parameter to allow selecting a Rust toolchain other

action.yml

@@ -40,7 +40,7 @@ runs:
       shell: bash
       run: set-cross-compile.sh ${{ inputs.target }}
     - name: Install toolchain if not cross-compiling
-      uses: dtolnay/rust-toolchain@stable
+      uses: dtolnay/rust-toolchain@master
       with:
         targets: ${{ inputs.target }}
         toolchain: ${{ inputs.toolchain }}