refactor(operator)!: Rename loki api go module

[periklis]

What this PR does / why we need it:
Renames the loki API module github.com/grafana/loki/operator/apis/loki to github.com/grafana/loki/operator/api/loki based on the migration changes from kubebuilder project layout go/v3 to go/v4/.

Follow up on:

• refactor(operator)!: Migrate project layout to kubebuilder go/v4 #14447

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[xperimental]

There's still references to the old path in config/docs/config.json. It does not seem to change anything in docs/operator/api.md or docs/operator/feature-gates.md when I change it and regenerate, so I'm not sure if this file is used / where it's used.