Fix benchmark workflow bugs

Author: kaitj

.github/workflows/benchmark.yaml

@@ -15,7 +15,7 @@ jobs:
           fetch-tags: true
           fetch-depth: 0
       - id: last_tag
-        run: echo ="tag=$(git describe --tags --abbrev=0)" >> $GITHUB_OUTPUT
+        run: echo "tag=$(git describe --tags --abbrev=0)" >> $GITHUB_OUTPUT
 
   benchmark:
     needs: get-tag
@@ -39,7 +39,7 @@ jobs:
       - name: Run benchmarks
         run: |
           uv run .github/scripts/run_benchmarks.py \ 
-            --output benchmark-${{matrix.target.name }}.json
+            --output benchmark-${{ matrix.target.name }}.json
       - uses: actions/upload-artifact@v7
         with:
           name: benchmark-${{ matrix.target.name }}