Fix rust hello world and example use cases CI

Signed-off-by: Andrew Wells <andrewmw94@gmail.com>

.github/workflows/ci.yml

@@ -57,15 +57,15 @@ jobs:
     uses: ./.github/workflows/run_example_use_cases_reusable.yml
     with:
       cedar_policy_ref: "refs/heads/main" # use the latest commit on main
-      cedar_examples_ref: "${{ github.head_ref }}" # use the current PR's commit
+      cedar_examples_ref: "${{ github.href }}" # use the current PR's commit
 
   build_rust_hello_world:
     name: rust_hello_world
     needs: get-branch-name
     uses: ./.github/workflows/build_rust_hello_world_reusable.yml
     with:
       cedar_policy_ref: "refs/heads/main" # use the latest commit on main
-      cedar_examples_ref: "${{ github.head_ref }}" # use the current PR's commit
+      cedar_examples_ref: "${{ github.href }}" # use the current PR's commit
 
   build_tiny_todo:
     name: tinytodo

.github/workflows/run_example_use_cases_reusable.yml

@@ -24,12 +24,6 @@ jobs:
         with:
           repository: cedar-policy/cedar-examples
           ref: ${{ inputs.cedar_examples_ref }}
-      - name: Checkout cedar-policy
-        uses: actions/checkout@v3
-        with:
-          repository: cedar-policy/cedar
-          ref: ${{ inputs.cedar_policy_ref }}
-          path: ./cedar
       - name: rustup
         run: rustup update ${{ matrix.toolchain }} && rustup default ${{ matrix.toolchain }}
       - name: build cli