SmallRye GraphQL extension's metrics are broken

[jmartisk]

The producer of vendor MetricRegistry is detected as unused (unless an application injects it directly, which makes no sense), but it is needed at runtime. This appears at application boot:

CDI: programmatic lookup problem detected
-----------------------------------------
At least one bean matched the required type and qualifiers but was marked as unused and removed during build
Removed beans:
	- PRODUCER_METHOD bean io.smallrye.metrics.MetricRegistries#getVendorRegistry() [types=[class org.eclipse.microprofile.metrics.MetricRegistry], qualifiers=[@org.eclipse.microprofile.metrics.annotation.RegistryType(type=VENDOR)]]
Required type: class org.eclipse.microprofile.metrics.MetricRegistry
Required qualifiers: [@org.eclipse.microprofile.metrics.annotation.RegistryType(type=VENDOR)]
Solutions:
	- Application developers can eliminate false positives via the @Unremovable annotation
	- Extensions can eliminate false positives via build items, e.g. using the UnremovableBeanBuildItem
	- See also https://quarkus.io/guides/cdi-reference#remove_unused_beans

Unfortunately, io.quarkus.smallrye.graphql.deployment.MetricsTest is unable to catch this error, because the test itself injects the vendor registry, therefore it's not unused and everything works....

[quarkusbot]

/cc @kenfinnigan, @phillip-kruger, @radcortez, @Ladicek
/cc @phillip-kruger