Use grep and not ggrep in filter-virtual-threads-tests-json.sh

[gsmet]

See https://github.com/quarkusio/quarkus/actions/runs/5672786922/job/15373773822

[quarkus-bot]

Failing Jobs - Building 5aeef32

Status	Name	Step	Failures	Logs	Raw logs
⌛	JVM Tests - JDK 11	Build	⚠️ Check →	Logs	Raw logs
⌛	JVM Tests - JDK 17	Build	⚠️ Check →	Logs	Raw logs
✖	JVM Tests - JDK 17 Windows	Build	Failures	Logs	Raw logs
✖	JVM Tests - JDK 20	Build	Failures	Logs	Raw logs
✔️	Maven Tests - JDK 11
⌛	Maven Tests - JDK 11 Windows	Build	⚠️ Check →	Logs	Raw logs
⌛	Native Tests - Security1	Build	⚠️ Check →	Logs	Raw logs
⌛	Native Tests - Security2	Build	⚠️ Check →	Logs	Raw logs

Full information is available in the Build summary check run.

Failures

⚙️ JVM Tests - JDK 17 Windows #

- Failing: extensions/grpc/deployment 
! Skipped: extensions/micrometer-registry-prometheus/deployment extensions/micrometer/deployment extensions/opentelemetry/deployment and 51 more

📦 extensions/grpc/deployment

✖ io.quarkus.grpc.server.blocking.BlockingOnClassTest.shouldOffloadBlockingOnSuperclassImplementation - More details - Source on GitHub

io.grpc.StatusRuntimeException: INTERNAL: Half-closed without a request
	at io.grpc.Status.asRuntimeException(Status.java:539)
	at io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:491)

---

⚙️ JVM Tests - JDK 20 #

- Failing: integration-tests/grpc-hibernate 

📦 integration-tests/grpc-hibernate

✖ com.example.grpc.hibernate.VertxBlockingMutinyTest.shouldAddItems - More details - Source on GitHub

io.smallrye.mutiny.CompositeException: 
Multiple exceptions caught:
	[Exception 0] io.grpc.StatusRuntimeException: INTERNAL: Half-closed without a request