This commit updates the `ScheduledTaskObservationDocumentation` to
better align the contributed KeyValues with OpenTelemetry conventions
for observations of code executions.
Instead of a "target.type" key with the bean class simple name, this
is now contributing the canonical class name of the bean under the
"code.namespace" key.
The "method.name" key is renamed to "code.function" and its values
remain unchanged.
Closes gh-30721
c2e3fed8dc