Pipeline config lookup points to the wrong folder for known pipelines

**Affected file:** `sk/search-strategy/bio-research/skills/nextflow-development/scripts/utils/validators.py`

### What I hit
I tried to validate a known pipeline name and got a false negative result, as if the pipeline did not exist.

I’m thinking this happens because `script_dir = Path(__file__).parent.parent.parent` moves too far up, so `config/pipelines` is searched in the wrong location.

### Repro
1. Call `load_pipeline_config("rnaseq")`.
2. Compare against an existing file under `skills/nextflow-development/scripts/config/pipelines`.
3. See lookup miss because the computed path is incorrect.

### Expected
Lookup should resolve to the actual `scripts/config/pipelines` path.

### Actual
Valid pipeline configs are treated as missing.

### Suggested fix
Adjust config path calculation to the actual script directory structure.