Bump version.vertx.grpc from 4.5.3 to 4.5.6

Bumps `version.vertx.grpc` from 4.5.3 to 4.5.6.

Updates `io.vertx:vertx-core` from 4.5.3 to 4.5.6
- [Commits](eclipse-vertx/vert.x@4.5.3...4.5.6)

Updates `io.vertx:vertx-grpc-client` from 4.5.3 to 4.5.6

---
updated-dependencies:
- dependency-name: io.vertx:vertx-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: io.vertx:vertx-grpc-client
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -20,7 +20,7 @@
         <version.microprofile.opentelemetry>1.1</version.microprofile.opentelemetry>
         <version.microprofile.config>3.0.3</version.microprofile.config>
         <version.resteasy>6.2.7.Final</version.resteasy>
-        <version.vertx.grpc>4.5.3</version.vertx.grpc>
+        <version.vertx.grpc>4.5.6</version.vertx.grpc>
         <micrometer.version>1.12.2</micrometer.version>
 
         <!-- Test -->