[3.15] Bump to Vert.x 4.5.21 and Netty 4.1.127.Final

[jponge]

This fixes Netty CVEs: CVE-2025-58057 and CVE-2025-58056

[quarkus-bot]

/cc @aloubyansky (3.15), @gastaldi (3.15), @gsmet (3.15), @jmartisk (3.15), @rsvoboda (3.15)

[gsmet]

Let's make sure we have everything sorted out in #49867 first before merging this.

[jponge]

@jmartisk updated here as well

[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit 89fe431.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

You can consult the Develocity build scans.

---

Flaky tests - Develocity

⚙️ JVM Tests - JDK 17

📦 extensions/smallrye-reactive-messaging/deployment

❌ io.quarkus.smallrye.reactivemessaging.hotreload.ConnectorChangeTest.testUpdatingConnector - History

• Expecting actual: ["-4","-5","-6","-7","-8","-9","-10","-11"] to start with: ["-3", "-4", "-5", "-6"] - java.lang.AssertionError

java.lang.AssertionError: 

Expecting actual:
  ["-4","-5","-6","-7","-8","-9","-10","-11"]
to start with:
  ["-3", "-4", "-5", "-6"]

	at io.quarkus.smallrye.reactivemessaging.hotreload.ConnectorChangeTest.testUpdatingConnector(ConnectorChangeTest.java:36)