feat(runtime): Remove unnecessary workspace subdirectory

[celarye]

Is a bit cleaner.

Before:

❯ tree plugins/
plugins/
├── binaries
│   ├── local
│   │   └── extension-requests
│   │       └── 0.1.0
│   │           └── plugin.wasm
│   └── remote
│       ├── celarye:automod-0.1.0.json
│       └── sha256:fa5a023919621b018b690e5447e5d8989a811f287db11522598c0590cd5be4e3
└── workspaces
    └── test
        ├── automod
        │   └── workspace
        └── extension-requests
            └── workspace

12 directories, 3 files

New:

❯ tree plugins/
plugins/
├── binaries
│   ├── local
│   │   └── extension-requests
│   │       └── 0.1.0
│   │           └── plugin.wasm
│   └── remote
│       ├── celarye:automod-0.1.0.json
│       └── sha256:fa5a023919621b018b690e5447e5d8989a811f287db11522598c0590cd5be4e3
└── workspaces
    └── test
        ├── automod
        └── extension-requests

10 directories, 3 files