.github/test-pr: increase parallelism with foundry testing

Author: ehildenb

.github/workflows/test-pr.yml

@@ -109,7 +109,7 @@ jobs:
       - name: 'Build Foundry'
         run: docker exec -t kevm-ci-foundry-${GITHUB_SHA} /bin/bash -c 'make build-foundry -j2'
       - name: 'Test Foundry'
-        run: docker exec -t kevm-ci-foundry-${GITHUB_SHA} /bin/bash -c 'make test-foundry -j2 FOUNDRY_PAR=4'
+        run: docker exec -t kevm-ci-foundry-${GITHUB_SHA} /bin/bash -c 'make test-foundry -j3 FOUNDRY_PAR=4'
       - name: 'Tear down Docker'
         if: always()
         run: |