CI: Delete rustup cache in case of any failures

This works around https://github.com/ATiltedTree/setup-rust/issues/157
and rust-lang/rustup#2417

.github/workflows/ci.yml

@@ -88,12 +88,12 @@ jobs:
 
   # Run the Rust integration tests.
   rs-tests:
-    uses: lf-lang/lingua-franca/.github/workflows/rs-tests.yml@master
+    uses: lf-lang/lingua-franca/.github/workflows/rs-tests.yml@ci-rust-fix
     needs: cancel
 
   # Run the Rust benchmark tests.
   rs-benchmark-tests:
-    uses: lf-lang/benchmarks-lingua-franca/.github/workflows/benchmark-tests.yml@ci-rust-fix
+    uses: lf-lang/benchmarks-lingua-franca/.github/workflows/benchmark-tests.yml@main
     with:
       target: 'Rust'
     needs: cancel

.github/workflows/rs-tests.yml

@@ -27,6 +27,17 @@ jobs:
       - name: Prepare build environment
         uses: ./.github/actions/prepare-build-env
       - name: Setup Rust
+        id: rustup
+        uses: ATiltedTree/setup-rust@v1
+        with:
+          rust-version: ${{ matrix.rust }}
+          components: clippy
+        continue-on-error: true
+      - name: Delete rustup cache
+        run: rm -rf ~/.rustup
+        if: ${{ steps.rustup.outcome }} != "success"
+      - name: Setup Rust (again)
+        if: ${{ steps.rustup.outcome }} != "success"
         uses: ATiltedTree/setup-rust@v1
         with:
           rust-version: ${{ matrix.rust }}