Fix e2e preparation script

Author: kateinoigakukun

.github/workflows/build-toolchain.yml

@@ -122,11 +122,12 @@ jobs:
           path: ./swift-test-results.tar.gz
 
       # Run e2e test
-      - name: Run E2E test
+      - name: Prepare E2E test
         working-directory: ${{ github.workspace }}/../
         run: |
-          tar xf swift-wasm-$TOOLCHAIN_CHANNEL-SNAPSHOT-${{ matrix.target }}.tar.gz
-          echo "TOOLCHAIN=$(find "$PWD" -name "swift-wasm-$TOOLCHAIN_CHANNEL-*" -type d)" >> $GITHUB_ENV
+          INSTALL_DIR=$(mktemp -d)
+          tar xf swift-wasm-$TOOLCHAIN_CHANNEL-SNAPSHOT-${{ matrix.target }}.tar.gz -C "$INSTALL_DIR"
+          echo "TOOLCHAIN=$(find "$INSTALL_DIR" -name "swift-wasm-$TOOLCHAIN_CHANNEL-*" -type d | head -n1)" >> $GITHUB_ENV
       - name: Build hello.wasm
         shell: bash
         if: ${{ matrix.build_hello_wasm }}