chore: Use slog in runtime package

[kalleep]

Pull Request Details

Start moving to use slog.Logger instead of go-kit/log.

This will only change usage in runtime and I will follow up with pr(s) to migrate component usage. Eventually we can get rid of some wrappers and clean-up it a bit.

Issue(s) fixed by this Pull Request

Part of: #4813

Notes to the Reviewer

PR Checklist

• Documentation added
• Tests updated
• Config converters updated

[Copilot]

Pull request overview

Migrates the runtime/controller logging flow from go-kit/log (+ logging/level) toward log/slog, as a first step in the broader effort to replace go-kit/log across the codebase.

Changes:

• Switched several runtime/controller log callsites from level.<X>(log.Logger).Log(...) to (*slog.Logger).<X>(...) and updated logger plumbing accordingly.
• Added (*logging.Logger).Slog() and a logging.NewSlogNop() helper to support slog.Logger usage while preserving dynamic logging updates.
• Updated controller scheduler tests to use slog-backed logging.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
internal/runtime/module.go	Stores/uses a *slog.Logger for module controller logging.
internal/runtime/logging/logger.go	Adds Slog() adapter and NewSlogNop() to produce *slog.Logger.
internal/runtime/internal/controller/scheduler.go	Converts scheduler/task logging and logger types to *slog.Logger.
internal/runtime/internal/controller/scheduler_test.go	Updates tests to use slog-backed loggers and validates warning/error output.
internal/runtime/internal/controller/node_custom_component.go	Removes unused go-kit logger plumbing from custom component node.
internal/runtime/internal/controller/node_config_logging.go	Types logging config node logger as *logging.Logger and removes casting.
internal/runtime/internal/controller/node_config_import.go	Converts import node logging to *slog.Logger (while still using go-kit logger for managed component options).
internal/runtime/internal/controller/node_config_foreach.go	Converts foreach node logging and helper signatures to *slog.Logger.
internal/runtime/internal/controller/loader.go	Converts loader logging and related helper signatures to *slog.Logger.
internal/runtime/internal/controller/component_references.go	Updates component reference warnings to use *slog.Logger.
internal/runtime/alloy.go	Switches runtime controller logger to *slog.Logger and updates log callsites.

[kgeckhart]

It's so nice to no longer have to do "msg", .............