This change integrates the OpenTelemetry Metrics API in the OpenDC
Workflow Service implementation. This replaces the old infrastructure for
gathering metrics.

This change integrates the OpenTelemetry Metrics API in the OpenDC
Compute Service implementation. This replaces the old infrastructure for
gathering metrics.

This change removes the dependency on the event tracer in
`opendc-trace`, since we are in the process of migrating OpenDC to
use OpenTelemetry for distributed tracing and metrics.

This change removes the opendc-core module. This module was an artifact
of the old codebase and remained mostly unused. This change removes all
usages of the module and if necessary introduces replacement classes.

This change removes the usage of bare-metal provisioning from the OpenDC
Compute module. This significantly simplifies the experiment setup.

This change moves the bare-metal provisioning packages outside the
compute module since these modules represent different layers in the
ecosystem and should not be mixed.

This change introduces the ComputeService interface (previously
VirtProvisioningService) and provides a central implementation in
opendc-compute-service.

Previously, the implementation of this interface was bound to the
simulator package, which meant that independent business logic could not
be re-used without importing the simulator code.

This change extracts the API for the OpenDC Compute service into a separate
module to establish a clearer boundary between the interface meant for
consumers and interfaces meant for the the serve implementation.